Đạo hàm của hàm số \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyEaiabg2 % da9maalaaabaGaci4yaiaac+gacaGGZbGaaGOmaiaadIhaaeaacaaI % ZaGaamiEaiabgUcaRiaaigdaaaaaaa!3FEA! y= \frac{{\cos 2x}}{{3x + 1}}\) là
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Lời giải:
Báo sai\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGabmyEayaafa % Gaeyypa0ZaaSaaaeaadaqadaqaaiGacogacaGGVbGaai4Caiaaikda % caWG4baacaGLOaGaayzkaaWaaWbaaSqabeaakiadacUHYaIOaaWaae % WaaeaacaaIZaGaamiEaiabgUcaRiaaigdaaiaawIcacaGLPaaacqGH % sisldaqadaqaaiaaiodacaWG4bGaey4kaSIaaGymaaGaayjkaiaawM % caamaaCaaaleqabaGccWaGGBOmGikaaiaac6cacaGGJbGaai4Baiaa % cohacaaIYaGaaiiEaaqaamaabmaabaGaaG4maiaadIhacqGHRaWkca % aIXaaacaGLOaGaayzkaaWaaWbaaSqabeaacaaIYaaaaaaakiabgkDi % ElaadMhacaGGNaGaeyypa0ZaaSaaaeaacqGHsislcaaIYaGaci4Cai % aacMgacaGGUbGaaGOmaiaadIhadaqadaqaaiaaiodacaWG4bGaey4k % aSIaaGymaaGaayjkaiaawMcaaiabgkHiTiaaiodaciGGJbGaai4Bai % aacohacaaIYaGaamiEaaqaamaabmaabaGaaG4maiaadIhacqGHRaWk % caaIXaaacaGLOaGaayzkaaWaaWbaaSqabeaacaaIYaaaaaaakiaac6 % caaaa!7713! y' = \frac{{{{\left( {\cos 2x} \right)}^\prime }\left( {3x + 1} \right) - {{\left( {3x + 1} \right)}^\prime }.cos2x}}{{{{\left( {3x + 1} \right)}^2}}} \Rightarrow y' = \frac{{ - 2\sin 2x\left( {3x + 1} \right) - 3\cos 2x}}{{{{\left( {3x + 1} \right)}^2}}}.\)