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:
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Lời giải:
Báo sai\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGabmyEayaafa % Gaeyypa0ZaaSaaaeaacqGHsislciGGZbGaaiyAaiaac6gacaWG4bWa % aeWaaeaacaaIXaGaeyOeI0Iaci4CaiaacMgacaGGUbGaamiEaaGaay % jkaiaawMcaaiabgUcaRiGacogacaGGVbGaai4CamaaCaaaleqabaGa % aGOmaaaakiaadIhaaeaadaqadaqaaiaaigdacqGHsislciGGZbGaai % yAaiaac6gacaWG4baacaGLOaGaayzkaaWaaWbaaSqabeaacaaIYaaa % aaaakiabg2da9maalaaabaGaaGymaaqaaiaaigdacqGHsislciGGZb % GaaiyAaiaac6gacaWG4baaaaaa!58C8! y' = \frac{{ - \sin x\left( {1 - \sin x} \right) + {{\cos }^2}x}}{{{{\left( {1 - \sin x} \right)}^2}}} = \frac{1}{{1 - \sin x}}\)
\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGabmyEayaafa % WaaeWaaeaadaWcaaqaaiabec8aWbqaaiaaiAdaaaaacaGLOaGaayzk % aaGaeyypa0ZaaSaaaeaacaaIXaaabaGaaGymaiabgkHiTiGacohaca % GGPbGaaiOBamaalaaabaGaeqiWdahabaGaaGOnaaaaaaGaeyypa0Ja % aGOmaaaa!45B4! y'\left( {\frac{\pi }{6}} \right) = \frac{1}{{1 - \sin \frac{\pi }{6}}} = 2\)