Hàm số \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaaeaaaaaaaaa8 % qacaWG5bGaeyypa0ZdamaabmaabaWdbiaadIhapaWaaWbaaSqabeaa % peGaaGOmaaaakiabgUcaRiaabccacaaIXaaapaGaayjkaiaawMcaam % aaCaaaleqabaWdbiaaiodaaaaaaa!3F17! y = {\left( {{x^2} + {\rm{ }}1} \right)^3}\) có đạo hàm cấp ba là:

Ta có \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyEaiabg2 % da9iaadIhadaahaaWcbeqaaiaaiAdaaaGccqGHRaWkcaaIZaGaamiE % amaaCaaaleqabaGaaGinaaaakiabgUcaRiaaiodacaWG4bWaaWbaaS % qabeaacaaIYaaaaOGaey4kaSIaaGymaaaa!42A9! y = {x^6} + 3{x^4} + 3{x^2} + 1\) 

\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGabmyEayaafa % Gaeyypa0JaaGOnaiaadIhadaahaaWcbeqaaiaaiwdaaaGccqGHRaWk % caaIXaGaaGOmaiaadIhadaahaaWcbeqaaiaaiodaaaGccqGHRaWkca % aI2aGaamiEaaaa!41A0! y' = 6{x^5} + 12{x^3} + 6x\)

\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGabmyEayaafy % aafaGaeyypa0JaaG4maiaaicdacaWG4bWaaWbaaSqabeaacaaI0aaa % aOGaey4kaSIaaG4maiaaiAdacaWG4bWaaWbaaSqabeaacaaIYaaaaO % Gaey4kaSIaaGOnaaaa!4169! y'' = 30{x^4} + 36{x^2} + 6\)

\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGabmyEayaafy % aafyaafaGaeyypa0JaaGymaiaaikdacaaIWaGaamiEamaaCaaaleqa % baGaaG4maaaakiabgUcaRiaaiEdacaaIYaGaamiEaiabg2da9iaaik % dacaaI0aWaaeWaaeaacaaI1aGaamiEamaaCaaaleqabaGaaGOmaaaa % kiabgUcaRiaaiodaaiaawIcacaGLPaaaaaa!47EF! y''' = 120{x^3} + 72x = 24\left( {5{x^2} + 3} \right)\)