Vi phân của hàm số \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyEaiabg2 % da9maalaaabaGaciiDaiaacggacaGGUbWaaOaaaeaacaWG4baaleqa % aaGcbaWaaOaaaeaacaWG4baaleqaaaaaaaa!3D12! y = \frac{{\tan \sqrt x }}{{\sqrt x }}\) là:

\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaeizaiaabM % hacqGH9aqpdaqadaqaamaalaaabaGaciiDaiaacggacaGGUbWaaOaa % aeaacaWG4baaleqaaaGcbaWaaOaaaeaacaWG4baaleqaaaaaaOGaay % jkaiaawMcaamaaCaaaleqabaGccWaGGBOmGikaaiaabsgacaqG4bGa % aGPaVlaab2dacaqGGaWaaSaaaeaadaWcaaqaaiaaigdaaeaacaaIYa % WaaOaaaeaacaWG4baaleqaaaaakiaac6cadaWcaaqaaiaaigdaaeaa % ciGGJbGaai4BaiaacohadaahaaWcbeqaaiaaikdaaaGcdaGcaaqaai % aadIhaaSqabaaaaOGaaiOlamaakaaabaGaamiEaaWcbeaakiabgkHi % TiGacshacaGGHbGaaiOBamaakaaabaGaamiEaaWcbeaakiaac6cada % WcaaqaaiaaigdaaeaacaaIYaWaaOaaaeaacaWG4baaleqaaaaaaOqa % aiaadIhaaaGaaeizaiaabIhacaqGGaaaaa!5E29! {\rm{dy}} = {\left( {\frac{{\tan \sqrt x }}{{\sqrt x }}} \right)^\prime }{\rm{dx}}\,{\rm{ = }}\frac{{\frac{1}{{2\sqrt x }}.\frac{1}{{{{\cos }^2}\sqrt x }}.\sqrt x - \tan \sqrt x .\frac{1}{{2\sqrt x }}}}{x}{\rm{dx }}\) \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaeypaiaabc % cadaqadaqaamaalaaabaGaaGymaaqaaiaaikdaaaGaaiOlamaalaaa % baGaaGymaaqaaiGacogacaGGVbGaai4CamaaCaaaleqabaGaaGOmaa % aakmaakaaabaGaamiEaaWcbeaaaaGccqGHsisldaWcaaqaaiGacoha % caGGPbGaaiOBamaakaaabaGaamiEaaWcbeaaaOqaaiGacogacaGGVb % Gaai4CamaakaaabaGaamiEaaWcbeaaaaGccaGGUaWaaSaaaeaacaaI % XaaabaGaaGOmamaakaaabaGaamiEaaWcbeaaaaaakiaawIcacaGLPa % aadaWcaaqaaiaaigdaaeaacaWG4baaaiaabsgacaqG4bGaaeiiaiaa % b2dadaWcaaqaamaakaaabaGaamiEaaWcbeaakiabgkHiTiGacohaca % GGPbGaaiOBamaakaaabaGaamiEaaWcbeaakiGacogacaGGVbGaai4C % amaakaaabaGaamiEaaWcbeaaaOqaaiaaikdacaWG4bWaaOaaaeaaca % WG4baaleqaaOGaaiOlaiGacogacaGGVbGaai4CamaaCaaaleqabaGa % aGOmaaaakmaakaaabaGaamiEaaWcbeaaaaGccaGGUaGaamizaiaadI % haaaa!673B! {\rm{ = }}\left( {\frac{1}{2}.\frac{1}{{{{\cos }^2}\sqrt x }} - \frac{{\sin \sqrt x }}{{\cos \sqrt x }}.\frac{1}{{2\sqrt x }}} \right)\frac{1}{x}{\rm{dx = }}\frac{{\sqrt x - \sin \sqrt x \cos \sqrt x }}{{2x\sqrt x .{{\cos }^2}\sqrt x }}.dx\) \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaaeypamaala % aabaGaaGOmamaakaaabaGaamiEaaWcbeaakiabgkHiTiGacohacaGG % PbGaaiOBaiaaikdadaGcaaqaaiaadIhaaSqabaaakeaacaaI0aGaam % iEamaakaaabaGaamiEaaWcbeaakiaac6caciGGJbGaai4Baiaacoha % daahaaWcbeqaaiaaikdaaaGcdaGcaaqaaiaadIhaaSqabaaaaOGaai % OlaiaadsgacaWG4baaaa!4954! {\rm{ = }}\frac{{2\sqrt x - \sin 2\sqrt x }}{{4x\sqrt x .{{\cos }^2}\sqrt x }}.dx\)