Cho hàm số \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOzamaabm % aabaGaamiEaaGaayjkaiaawMcaaiabg2da9iGacohacaGGPbGaaiOB % amaaCaaaleqabaGaaG4maaaakiaadIhacqGHRaWkcaWG4bWaaWbaaS % qabeaacaaIYaaaaaaa!41FC! f\left( x \right) = {\sin ^3}x + {x^2}\). Giá trị \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGabmOzayaaga % WaaeWaaeaadaWcaaqaaiabec8aWbqaaiaaikdaaaaacaGLOaGaayzk % aaaaaa!3AFE! f''\left( {\frac{\pi }{2}} \right)\) bằng
Suy nghĩ và trả lời câu hỏi trước khi xem đáp án
Lời giải:
Báo sai\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGabmOzayaafa % WaaeWaaeaacaWG4baacaGLOaGaayzkaaGaeyypa0JaaG4maiaaboha % caqGPbGaaeOBamaaCaaaleqabaGaaGOmaaaakiaadIhacaqGJbGaae % 4BaiaabohacaWG4bGaey4kaSIaaGOmaiaadIhaaaa!465D! f'\left( x \right) = 3{\rm{si}}{{\rm{n}}^2}x{\rm{cos}}x + 2x\)
\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGabmOzayaaga % WaaeWaaeaacaWG4baacaGLOaGaayzkaaGaeyypa0JaaGOnaiaaboha % caqGPbGaaeOBaiaadIhacaqGJbGaae4BaiaabohadaahaaWcbeqaai % aaikdaaaGccaWG4bGaeyOeI0IaaG4maiaabohacaqGPbGaaeOBamaa % CaaaleqabaGaaG4maaaakiaadIhacqGHRaWkcaaIYaaaaa!4BD2! f''\left( x \right) = 6{\rm{sin}}x{\rm{co}}{{\rm{s}}^2}x - 3{\rm{si}}{{\rm{n}}^3}x + 2\)
\(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeyO0H4Tabm % OzayaagaWaaeWaaeaadaWcaaqaaiabec8aWbqaaiaaikdaaaaacaGL % OaGaayzkaaGaeyypa0JaeyOeI0IaaGymaaaa!4008! \Rightarrow f''\left( {\frac{\pi }{2}} \right) = - 1\)