Hàm số \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyEaiabg2 % da9maakaaabaGaci4yaiaac+gacaGG0bGaaGOmaiaadIhaaSqabaaa % aa!3CA0! y = \sqrt {\cot 2x} \) có đạo hàm là:
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Lời giải:
Báo sai\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyEaiaacE % cacqGH9aqpdaqadaqaaiGacogacaGGVbGaaiiDaiaaikdacaWG4baa % caGLOaGaayzkaaGaai4jamaalaaabaGaaGymaaqaaiaaikdadaGcaa % qaaiGacogacaGGVbGaaiiDaiaaikdacaWG4baaleqaaaaakiabg2da % 9iabgkHiTiaaikdacaGGUaWaaSaaaeaacaaIXaaabaGaci4CaiaacM % gacaGGUbWaaWbaaSqabeaacaaIYaaaaOGaaGOmaiaadIhaaaGaaiOl % amaalaaabaGaaGymaaqaaiaaikdadaGcaaqaaiGacogacaGGVbGaai % iDaiaaikdacaWG4baaleqaaaaakiabg2da9maalaaabaGaeyOeI0Ya % aeWaaeaacaaIXaGaey4kaSIaci4yaiaac+gacaGG0bWaaWbaaSqabe % aacaaIYaaaaOGaaGOmaiaadIhaaiaawIcacaGLPaaaaeaadaGcaaqa % aiGacogacaGGVbGaaiiDaiaaikdacaWG4baaleqaaaaaaaa!6589! y' = \left( {\cot 2x} \right)'\frac{1}{{2\sqrt {\cot 2x} }} = - 2.\frac{1}{{{{\sin }^2}2x}}.\frac{1}{{2\sqrt {\cot 2x} }} = \frac{{ - \left( {1 + {{\cot }^2}2x} \right)}}{{\sqrt {\cot 2x} }}\)