Trắc nghiệm Phương trình lượng giác cơ bản Toán Lớp 11
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Câu 1:
Phương trình \(\sin 2 x \cdot(2 \sin x-\sqrt{2})=0\) có nghiệm là
A. \(\begin{array}{l} {\left[\begin{array}{l} x=k \frac{\pi}{2} \\ x=\frac{\pi}{4}+k 2 \pi\\ x=\frac{3 \pi}{4}+k 2 \pi \end{array}\right.} \\ \end{array}\)
B. \(\left[\begin{array}{l} x=k \frac{\pi}{2} \\ x=\frac{\pi}{4}+k \pi \\ x=\frac{3 \pi}{4}+k \pi \end{array}\right.\)
C. \(\left[\begin{array}{l} x=k \pi \\ x=\frac{\pi}{4}+k 2 \pi \\ x=\frac{3 \pi}{4}+k 2 \pi \end{array}\right.\)
D. \(\left[\begin{array}{l} x=k \frac{\pi}{2} \\ x=\frac{\pi}{4}+k 2 \pi \\ x=-\frac{\pi}{4}+k 2 \pi \end{array}\right.\)
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Câu 2:
Phương trình \((\sin x+1)(\sin x-\sqrt{2})=0\) có nghiệm là:
A. \(x=-\frac{\pi}{2}+k 2 \pi(k \in \mathbb{Z})\)
B. \(x=\pm \frac{\pi}{4}+k 2 \pi, x=-\frac{\pi}{8}+k \pi(k \in \mathbb{Z})\)
C. \(x=\frac{\pi}{2}+k 2 \pi\)
D. \(x=\pm \frac{\pi}{2}+k 2 \pi\)
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Câu 3:
Phương trình: \(\tan \left(\frac{\pi}{2}-x\right)+2 \tan \left(2 x+\frac{\pi}{2}\right)=1\) có nghiệm là:
A. \(x=\frac{\pi}{4}+k 2 \pi(k \in \mathbb{Z})\)
B. \(x=\frac{\pi}{4}+k \pi(k \in \mathbb{Z})\)
C. \(x=\frac{\pi}{4}+k \frac{\pi}{2}(k \in \mathbb{Z})\)
D. \(x=\pm \frac{\pi}{4}+k \pi(k \in \mathbb{Z})\)
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Câu 4:
Phương trình nào sau đây vô nghiệm
A. \(\tan x=3\)
B. \(\cot x=1\)
C. \(\cos x=0\)
D. \(\sin x=\frac{4}{3}\)
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Câu 5:
Nghiệm của phương trình \(\tan 4 x \cdot \cot 2 x=1\) là:
A. \(k \pi, k \in \mathbb{Z}\)
B. \(\frac{\pi}{4}+k \frac{\pi}{2}, k \in \mathbb{Z}\)
C. \(k \frac{\pi}{2}, k \in \mathbb{Z}\)
D. Vô nghiệm.
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Câu 6:
Nghiệm của phương trình \(\tan 3 x \cdot \cot 2 x=1\) là
A. \(k \frac{\pi}{2}, k \in \mathbb{Z}\)
B. \(-\frac{\pi}{4}+k \frac{\pi}{2}, k \in \mathbb{Z}\)
C. \(k \pi, k \in \mathbb{Z}\)
D. Vô nghiệm.
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Câu 7:
Giải phương trình \(\tan 3 x \tan x=1\)
A. \(x=\frac{\pi}{8}+k \frac{\pi}{8} ; k \in \mathbb{Z}\)
B. \(x=\frac{\pi}{4}+k \frac{\pi}{4} ; k \in \mathbb{Z}\)
C. \(x=\frac{\pi}{8}+k \frac{\pi}{4} ; k \in \mathbb{Z}\)
D. \(x=\frac{\pi}{8}+k \frac{\pi}{2} ; k \in \mathbb{Z}\)
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Câu 8:
Phương trình \(\tan x \cdot \cot x=1\) có tập nghiệm là
A. \(T=\mathbb{R} \backslash\left\{\frac{k \pi}{2} ; k \in \mathbb{Z}\right\}\)
B. \(T=\mathbb{R} \backslash\left\{\frac{\pi}{2}+k \pi ; k \in \mathbb{Z}\right\}\)
C. \(T=\mathbb{R} \backslash\{\pi+k \pi ; k \in \mathbb{Z}\}\)
D. \(T=\mathbb{R}\)
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Câu 9:
Nghiệm của phương trình \(\cot \left(\frac{x}{4}+10^{\circ}\right)=-\sqrt{3}(\text { vói } k \in \mathbb{Z}) \text { là }\)
A. \(x=-200^{\circ}+k 360^{\circ}\)
B. \(x=-200^{\circ}+k 720^{\circ}\)
C. \(x=-20^{\circ}+k 360^{\circ}\)
D. \(x=-160^{\circ}+k 720^{\circ}\)
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Câu 10:
Giải phương trình \(\sqrt{3} \cot \left(5 x-\frac{\pi}{8}\right)=0\)
A. \(x=\frac{\pi}{8}+k \pi ; k \in \mathbb{Z}\)
B. \(x=\frac{\pi}{8}+k \frac{\pi}{5} ; k \in \mathbb{Z}\)
C. \(x=\frac{\pi}{8}+k \frac{\pi}{4} ; k \in \mathbb{Z}\)
D. \(x=\frac{\pi}{8}+k \frac{\pi}{2} ; k \in \mathbb{Z}\)
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Câu 11:
Nghiệm của phương trình \(\cot \left(x+\frac{\pi}{4}\right)=\sqrt{3}\)
A. \(x=\frac{\pi}{12}+k \pi\)
B. \(x=\frac{\pi}{3}+k \pi\)
C. \(x=-\frac{\pi}{12}+k \pi\)
D. \(x=\frac{\pi}{6}+k \pi\)
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Câu 12:
Phương trình lượng giác: \(2 \cot x-\sqrt{3}=0\) có nghiệm là
A. \(\left[\begin{array}{l} x=\frac{\pi}{6}+k 2 \pi \\ x=\frac{-\pi}{6}+k 2 \pi \end{array}\right.\)
B. \(x=\operatorname{arccot} \frac{\sqrt{3}}{2}+k \pi\)
C. \(x=\frac{\pi}{6}+k \pi\)
D. \(x=\frac{\pi}{3}+k \pi\)
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Câu 13:
Cho hàm số \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOzamaabm % aabaGaamiEaaGaayjkaiaawMcaaiabg2da9iGacshacaGGHbGaaiOB % amaabmaabaGaamiEaiabgkHiTmaalaaabaGaaGOmaiabec8aWbqaai % aaiodaaaaacaGLOaGaayzkaaaaaa!43F4! f\left( x \right) = \tan \left( {x - \frac{{2\pi }}{3}} \right)\). Giá trị f'(0) bằng
A. 3
B. 4
C. -3
D. -4
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Câu 14:
Cho hàm số \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyEaiabg2 % da9iaadAgadaqadaqaaiaadIhaaiaawIcacaGLPaaacqGH9aqpciGG % ZbGaaiyAaiaac6gadaahaaWcbeqaaiaaiodaaaGccaaI1aGaamiEai % aac6caciGGJbGaai4BaiaacohadaahaaWcbeqaaiaaikdaaaGcdaWc % aaqaaiaadIhaaeaacaaIZaaaaaaa!4839! y = f\left( x \right) = {\sin ^3}5x.{\cos ^2}\frac{x}{3}\). Giá trị đúng của \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGabmOzayaafa % WaaeWaaeaadaWcaaqaaiabec8aWbqaaiaaikdaaaaacaGLOaGaayzk % aaaaaa!3AFD! f'\left( {\frac{\pi }{2}} \right)\) bằng
A. \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeyOeI0YaaS % aaaeaadaGcaaqaaiaaiodaaSqabaaakeaacaaI2aaaaiabgwSixdaa % !3ADD! - \frac{{\sqrt 3 }}{6} \cdot \)
B. \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeyOeI0YaaS % aaaeaadaGcaaqaaiaaiodaaSqabaaakeaacaaI2aaaaiabgwSixdaa % !3ADD! - \frac{{\sqrt 3 }}{4} \cdot \)
C. \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeyOeI0YaaS % aaaeaadaGcaaqaaiaaiodaaSqabaaakeaacaaI2aaaaiabgwSixdaa % !3ADD! - \frac{{\sqrt 3 }}{3} \cdot\)
D. \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeyOeI0YaaS % aaaeaadaGcaaqaaiaaiodaaSqabaaakeaacaaI2aaaaiabgwSixdaa % !3ADD! - \frac{{\sqrt 3 }}{2} \cdot \)
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Câu 15:
Cho hàm số \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyEaiabg2 % da9iaadAgacaGGOaGaamiEaiaacMcacqGH9aqpdaWcaaqaaiGacoga % caGGVbGaai4CamaaCaaaleqabaGaaGOmaaaakiaadIhaaeaacaaIXa % Gaey4kaSIaci4CaiaacMgacaGGUbWaaWbaaSqabeaacaaIYaaaaOGa % amiEaaaaaaa!4777! y = f(x) = \frac{{{{\cos }^2}x}}{{1 + {{\sin }^2}x}}\). Giá trị \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOzamaabm % aabaWaaSaaaeaacqaHapaCaeaacaaI0aaaaaGaayjkaiaawMcaaiab % gkHiTiaaiodaceWGMbGbauaadaqadaqaamaalaaabaGaeqiWdahaba % GaaGinaaaaaiaawIcacaGLPaaaaaa!41A8! f\left( {\frac{\pi }{4}} \right) - 3f'\left( {\frac{\pi }{4}} \right)\) là:
A. -3
B. \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaSaaaeaaca % aI4aaabaGaaG4maaaacqGHflY1aaa!39CD! \frac{8}{3} \cdot \)
C. 3
D. \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaSaaaeaaca % aI4aaabaGaaG4maaaacqGHflY1aaa!39CD! -\frac{8}{3} \cdot \)
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Câu 16:
Cho hàm số \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyEaiabg2 % da9maalaaabaGaci4yaiaac+gacaGGZbGaamiEaaqaaiaaigdacqGH % sislciGGZbGaaiyAaiaac6gacaWG4baaaaaa!4155! y = \frac{{\cos x}}{{1 - \sin x}}\). Tính \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGabmyEayaafa % WaaeWaaeaadaWcaaqaaiabec8aWbqaaiaaiAdaaaaacaGLOaGaayzk % aaaaaa!3B14! y'\left( {\frac{\pi }{6}} \right)\) bằng:
A. 1
B. -1
C. 2
D. -2
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Câu 17:
Cho hàm số \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyEaiabg2 % da9iaadAgadaqadaqaaiaadIhaaiaawIcacaGLPaaacqGH9aqpciGG % 0bGaaiyyaiaac6gadaqadaqaaiaadIhacqGHsisldaWcaaqaaiaaik % dacqaHapaCaeaacaaIZaaaaaGaayjkaiaawMcaaaaa!45F9! y = f\left( x \right) = \tan \left( {x - \frac{{2\pi }}{3}} \right)\). Giá trị f'(0) bằng:
A. 4
B. \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaOaaaeaaca % aIZaaaleqaaaaa!36CC! \sqrt 3 \)
C. \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaOaaaeaaca % aIZaaaleqaaaaa!36CC! -\sqrt 3 \)
D. 3
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Câu 18:
Xét hàm số \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyEaiabg2 % da9iaadAgadaqadaqaaiaadIhaaiaawIcacaGLPaaacqGH9aqpcaaI % YaGaci4CaiaacMgacaGGUbWaaeWaaeaadaWcaaqaaiaaiwdacqaHap % aCaeaacaaI2aaaaiabgUcaRiaadIhaaiaawIcacaGLPaaaaaa!46B7! y = f\left( x \right) = 2\sin \left( {\frac{{5\pi }}{6} + x} \right)\). Tính giá trị \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOzaiaacE % cadaqadaqaamaalaaabaGaeqiWdahabaGaaGOnaaaaaiaawIcacaGL % Paaaaaa!3BA0! f'\left( {\frac{\pi }{6}} \right)\) bằng:
A. -1
B. 0
C. -2
D. 2
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Câu 19:
Cho hàm số \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyEaiabg2 % da9iaadAgadaqadaqaaiaadIhaaiaawIcacaGLPaaacqGH9aqpdaWc % aaqaaiaaigdaaeaadaGcaaqaaiGacohacaGGPbGaaiOBaiaadIhaaS % qabaaaaaaa!412A! y = f\left( x \right) = \frac{1}{{\sqrt {\sin x} }}\). Giá trị \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOzaiaacE % cadaqadaqaamaalaaabaGaeqiWdahabaGaaGOmaaaaaiaawIcacaGL % Paaaaaa!3B9C! f'\left( {\frac{\pi }{2}} \right)\) bằng:
A. 1
B. -1
C. 0
D. không tồn tại
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Câu 20:
Cho hàm số \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyEaiabg2 % da9iaadAgadaqadaqaaiaadIhaaiaawIcacaGLPaaacqGH9aqpdaGc % aaqaaiGacshacaGGHbGaaiOBaiaadIhacqGHRaWkciGGJbGaai4Bai % aacshacaWG4baaleqaaaaa!450B! y = f\left( x \right) = \sqrt {\tan x + \cot x} \). Giá trị \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOzaiaacE % cadaqadaqaamaalaaabaGaeqiWdahabaGaaGinaaaaaiaawIcacaGL % Paaaaaa!3B9E! f'\left( {\frac{\pi }{4}} \right)\) bằng:
A. \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaSaaaeaada % GcaaqaaiaaikdaaSqabaaakeaacaaIYaaaaaaa!37A1! \sqrt 2\)
B. \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaSaaaeaada % GcaaqaaiaaikdaaSqabaaakeaacaaIYaaaaaaa!37A1! \frac{{\sqrt 2 }}{2}\)
C. 0
D. \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaSaaaeaada % GcaaqaaiaaikdaaSqabaaakeaacaaIYaaaaaaa!37A1! \frac{1}{2}\)
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Câu 21:
Cho hàm số \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyEaiabg2 % da9iaadAgadaqadaqaaiaadIhaaiaawIcacaGLPaaacqGH9aqpciGG % ZbGaaiyAaiaac6gadaGcaaqaaiaadIhaaSqabaGccqGHRaWkciGGJb % Gaai4BaiaacohadaGcaaqaaiaadIhaaSqabaaaaa!4536! y = f\left( x \right) = \sin \sqrt x + \cos \sqrt x \). Giá trị \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOzaiaacE % cadaqadaqaamaalaaabaGaeqiWda3aaWbaaSqabeaacaaIYaaaaaGc % baGaaGymaiaaiAdaaaaacaGLOaGaayzkaaaaaa!3D4E! f'\left( {\frac{{{\pi ^2}}}{{16}}} \right)\) bằng:
A. 0
B. \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaOaaaeaaca % aIYaaaleqaaaaa!36CB! \sqrt 2 \)
C. \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaSaaaeaaca % aIYaaabaGaeqiWdahaaaaa!387D! \frac{2}{\pi }\)
D. \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaSaaaeaaca % aIYaWaaOaaaeaacaaIYaaaleqaaaGcbaGaeqiWdahaaaaa!395E! \frac{{2\sqrt 2 }}{\pi }\)
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Câu 22:
Cho hàm số \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyEaiabg2 % da9maalaaabaGaci4yaiaac+gacaGGZbGaaGOmaiaadIhaaeaacaaI % XaGaeyOeI0Iaci4CaiaacMgacaGGUbGaamiEaaaaaaa!4211! y = \frac{{\cos 2x}}{{1 - \sin x}}\). Tính \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyEaiaacE % cadaqadaqaamaalaaabaGaeqiWdahabaGaaGOnaaaaaiaawIcacaGL % Paaaaaa!3BB3! y'\left( {\frac{\pi }{6}} \right)\) bằng:
A. 1
B. -1
C. \(\sqrt3\)
D. \(-\sqrt3\)
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Câu 23:
Cho hàm số y = cos3x.sin 2x .Tính \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyEaiaacE % cadaqadaqaamaalaaabaGaeqiWdahabaGaaG4maaaaaiaawIcacaGL % Paaaaaa!3BB0! y'\left( {\frac{\pi }{3}} \right)\) bằng
A. -1
B. 1
C. \(\frac{1}{2}\)
D. \(\frac{-1}{2}\)
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Câu 24:
Hàm số \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyEaiabg2 % da9iaadAgadaqadaqaaiaadIhaaiaawIcacaGLPaaacqGH9aqpdaWc % aaqaaiaaikdaaeaaciGGJbGaai4Baiaacohadaqadaqaaiabec8aWj % aadIhaaiaawIcacaGLPaaaaaaaaa!4451! y = f\left( x \right) = \frac{2}{{\cos \left( {\pi x} \right)}}\) có f'(3) bằng:
A. \(2\pi\)
B. \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaSaaaeaaca % aI4aGaeqiWdahabaGaaG4maaaaaaa!3940! \frac{{8\pi }}{3}\)
C. \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaSaaaeaaca % aI0aWaaOaaaeaacaaIZaaaleqaaaGcbaGaaG4maaaaaaa!3861! \frac{{4\sqrt 3 }}{3}\)
D. 0
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Câu 25:
Cho phương trình \(\cos ^{2}\left(\frac{x}{2}-\frac{\pi}{4}\right)=m\) . Tìm m để phương trình có nghiệm?
A. \(m \leq 1\)
B. \(0 \leq m \leq 1\)
C. \(-1 \leq m \leq 1\)
D. \(m \geq 0\)
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Câu 26:
Cho phương trình: \(\cos \left(2 x-\frac{\pi}{3}\right)-m=2\) . Với giá trị nào của m thì phương trình có nghiệm
A. Không tồn tại m.
B. \(m \in[-1 ; 3]\)
C. \(m \in[-3 ;-1]\)
D. mọi giá trị của m.
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Câu 27:
Phương trình \(\cos x=m+1\) có nghiệm khi m là
A. \(-1 \leq m \leq 1\)
B. \(m \leq 0\)
C. \(m \geq-2\)
D. \(-2 \leq m \leq 0\)
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Câu 28:
Phương trình \(m \cos x+1=0\) có nghiệm khi m thỏa điều kiện
A. \(\left[\begin{array}{l}m \leq-1 \\ m \geq 1\end{array}\right.\)
B. \(m \geq 1\)
C. \(m \geq-1\)
D. \(\left[\begin{array}{l}m \leq 1 \\ m \geq-1\end{array}\right.\)
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Câu 29:
Cho phương trình: \(\sqrt{3} \cos x+m-1=0\). Với giá trị nào của m thì phương trình có nghiệm:
A. \(m<1-\sqrt{3}\)
B. \(m>1+\sqrt{3}\)
C. \(1-\sqrt{3} \leq m \leq 1+\sqrt{3}\)
D. \(-\sqrt{3} \leq m \leq \sqrt{3}\)
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Câu 30:
Phương trình \(\cos x-m=0\) vô nghiệm khi m là:
A. \(\left[\begin{array}{l}m<-1 \\ m>1\end{array}\right.\)
B. m>1
C. \(-1 \leq m \leq 1\)
D. m<-1
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Câu 31:
Nghiệm của phương trình \(cot x+\sqrt{3}=0\)$ là:
A. \(x=-\frac{\pi}{3}+k \pi\)
B. \(x=-\frac{\pi}{6}+k \pi\)
C. \(x=\frac{\pi}{3}+k 2 \pi\)
D. \(x=\frac{\pi}{6}+k \pi\)
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Câu 32:
Nghiệm phương trình\(1+\cot x=0\) là:
A. \(x=\frac{\pi}{4}+k \pi\)
B. \(x=-\frac{\pi}{4}+k \pi\)
C. \(x=\frac{\pi}{4}+k 2 \pi\)
D. \(x=-\frac{\pi}{4}+k 2 \pi\)
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Câu 33:
Giải phương trình: \(\tan ^{2} x=3\)có nghiệm là
A. \(\mathrm{x}=-\frac{\pi}{3}+k \pi\)
B. \({x}=\pm \frac{\pi}{3}+k \pi\)
C. Vô nghiệm
D. \(x=\frac{\pi}{3}+k \pi\)
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Câu 34:
Nghiệm của phương trình \(\tan \left(2 x-15^{\circ}\right)=1\, với \,-90^{\circ}<x<90^{\circ}\) là
A. \(x=-30^{0}\)
B. \(x=-60^{\circ}\)
C. \(x=30^{0}\)
D. \(x=-60^{\circ}, x=30^{\circ}\)
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Câu 35:
Phương trình \(\tan \left(2 x+12^{\circ}\right)=0\) có nghiệm là
A. \(x=-6^{\circ}+k 90^{\circ},(k \in \mathbb{Z})\)
B. \(x=-6^{\circ}+k 180^{\circ},(k \in \mathbb{Z})\)
C. \(x=-6^{\circ}+k 360^{\circ},(k \in \mathbb{Z})\)
D. \(x=-12^{\circ}+k 90^{\circ},(k \in \mathbb{Z})\)
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Câu 36:
Nghiệm của phương trình \(3 \tan \frac{x}{4}-\sqrt{3}=0\) trong nữa khoảng \([0 ; 2 \pi)\) là
A. \(\left\{\frac{\pi}{3} ; \frac{2 \pi}{3}\right\}\)
B. \(\left\{\frac{3 \pi}{2}\right\}\)
C. \(\left\{\frac{\pi}{2} ; \frac{3 \pi}{2}\right\}\)
D. \(\left\{\frac{2 \pi}{3}\right\}\)
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Câu 37:
Giải phương trình \(\sqrt{3} \tan \left(3 x+\frac{3 \pi}{5}\right)=0\)
A. \(x=\frac{\pi}{8}+k \frac{\pi}{4} ; k \in \mathbb{Z}\)
B. \(x=-\frac{\pi}{5}+k \frac{\pi}{4} ; k \in \mathbb{Z}\)
C. \(x=-\frac{\pi}{5}+k \frac{\pi}{2} ; k \in \mathbb{Z}\)
D. \(x=-\frac{\pi}{5}+k \frac{\pi}{3} ; k \in \mathbb{Z}\)
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Câu 38:
Phurong trình lurơng giác: \(\sqrt{3}\tan x-3=0\) có nghiệm là
A. \(x=\frac{\pi}{3}+k \pi\)
B. \(x=-\frac{\pi}{3}+k 2 \pi\)
C. \(x=\frac{\pi}{6}+k \pi\)
D. \(x=-\frac{\pi}{3}+k \pi\)
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Câu 39:
Họ nghiệm của phương trình \(\tan 2 x-\tan x=0\) là
A. \(\frac{-\pi}{6}+k \pi, k \in \mathbb{Z}\)
B. \(\frac{\pi}{3}+k \pi, k \in \mathbb{Z}\)
C. \(\frac{\pi}{6}+k \pi, k \in \mathbb{Z}\)
D. \(k \pi, k \in \mathbb{Z}\)
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Câu 40:
Nghiệm của phương trình \(\tan x=4 \text { là }\)
A. \(x=\arctan 4+k \pi\)
B. \(x=\arctan 4+k 2 \pi\)
C. \(x=4+k \pi\)
D. \(x=\frac{\pi}{4}+k \pi\)
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Câu 41:
Nghiệm của phương trình \(\sqrt{3} \tan 3 x-3=0(\operatorname{với} k \in \mathbb{Z})\) là
A. \(x=\frac{\pi}{9}+\frac{k \pi}{9}\)
B. \(x=\frac{\pi}{3}+\frac{k \pi}{3}\)
C. \(x=\frac{\pi}{3}+\frac{k \pi}{9}\)
D. \(x=\frac{\pi}{9}+\frac{k \pi}{3}\)
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Câu 42:
Phương trình lượng giác: \(\sqrt{3} \cdot \tan x+3=0\)có nghiệm là
A. \(x=\frac{\pi}{3}+k \pi\)
B. \(x=-\frac{\pi}{3}+k 2 \pi\)
C. \( \mathbf{x}=\frac{\pi}{6}+k \pi\)
D. \(x=-\frac{\pi}{3}+k \pi\)
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Câu 43:
Phương trình \(\sqrt{3}+\tan x=0\) có nghiệm.
A. \(x=\frac{\pi}{3}+k \pi\)
B. \(x=-\frac{\pi}{3}+k \pi\)
C. \(x=\frac{\pi}{3}+k 2 \pi ; x=\frac{2 \pi}{3}+k 2 \pi\)
D. \(x=-\frac{\pi}{3}+k 2 \pi ; x=\frac{4 \pi}{3}+k 2 \pi\)
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Câu 44:
Nghiệm của phương trình \(\sqrt{3}+3 \tan x=0\)
A. \(x=\frac{\pi}{3}+k \pi\)
B. \(x=\frac{\pi}{2}+k 2 \pi\)
C. \(x=-\frac{\pi}{6}+k \pi\)
D. \(x=\frac{\pi}{2}+k \pi\)
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Câu 45:
Phương trình \(\tan x=\tan \frac{x}{2}\)có họ nghiệm là
A. \(x=k 2 \pi(k \in \mathbb{Z})\)
B. \(x=k \pi(k \in \mathbb{Z})\)
C. \(x=\pi+k 2 \pi(k \in \mathbb{Z})\)
D. \(x=-\pi+k 2 \pi(k \in \mathbb{Z})\)
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Câu 46:
Họ nghiệm của phương trình \(\tan \left(x+\frac{\pi}{5}\right)+\sqrt{3}=0\) là:
A. \(\frac{8 \pi}{15}+k \pi ; k \in \mathbb{Z}\)
B. \(-\frac{8 \pi}{15}+k \pi ; k \in \mathbb{Z}\)
C. \(-\frac{8 \pi}{15}+k 2 \pi ; k \in \mathbb{Z}\)
D. \(\frac{8 \pi}{15}+k 2 \pi ; k \in \mathbb{Z}\)
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Câu 47:
Nghiệm phương trình \(1+\tan x=0\)
A. \(x=\frac{\pi}{4}+k \pi\)
B. \(x=-\frac{\pi}{4}+k \pi\)
C. \(x=\frac{\pi}{4}+k 2 \pi\)
D. \(x=-\frac{\pi}{4}+k 2 \pi\)
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Câu 48:
Các họ nghiệm của phương trình \(\sin 2 x-\cos x=0\) là:
A. \(\frac{\pi}{6}+k \frac{2 \pi}{3} ; \frac{\pi}{2}+k 2 \pi ; k \in \mathbb{Z}\)
B. \(\frac{-\pi}{6}+k \frac{2 \pi}{3} ; \frac{\pi}{2}+k 2 \pi ; k \in \mathbb{Z}\)
C. \(\frac{\pi}{6}+k \frac{2 \pi}{3} ; \frac{-\pi}{2}+k 2 \pi ; k \in \mathbb{Z}\)
D. \(\frac{-\pi}{6}+k \frac{2 \pi}{3} ; \frac{-\pi}{2}+k 2 \pi ; k \in \mathbb{Z}\)
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Câu 49:
Nghiệm của phương trình \(\sin x \cdot \cos x=0\) là:
A. \(x=\frac{\pi}{2}+k 2 \pi\)
B. \(x=k \frac{\pi}{2}\)
C. \(x=k 2 \pi\)
D. \(x=\frac{\pi}{6}+k 2 \pi\)
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Câu 50:
Số nghiệm của phương trình \(\sin x=\cos x \text { trong đoạn }[-\pi ; \pi]\) là
A. 2
B. 4
C. 5
D. 6
