Tính tích phân \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamysaiabg2 % da9maapehabaGaamiEaiGacogacaGGVbGaai4CaiaadIhacaaMc8Ua % aeizaiaadIhaaSqaaiaaicdaaeaadaWcaaqaaiabec8aWbqaaiaaik % daaaaaniabgUIiYdaaaa!45B0! I = \int\limits_0^{\frac{\pi }{2}} {x\cos x\,{\rm{d}}x} \)
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Lời giải:
Báo sai\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaiqaaqaabe % qaaiaadwhacqGH9aqpcaWG4baabaGaamizaiaadAhacqGH9aqpciGG % JbGaai4BaiaacohacaWG4bGaaGPaVlaadsgacaWG4baaaiaawUhaaa % aa!443D! \left\{ \begin{array}{l} u = x\\ dv = \cos x\,dx \end{array} \right.\)\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeyO0H49aai % qaaqaabeqaaiaadsgacaWG1bGaeyypa0JaamizaiaadIhaaeaacaWG % 2bGaeyypa0Jaci4CaiaacMgacaGGUbGaaGPaVlaadIhaaaGaay5Eaa % aaaa!45A2! \Rightarrow \left\{ \begin{array}{l} du = dx\\ v = \sin \,x \end{array} \right.\)
\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamysaiabg2 % da9maaeiaabaGaamiEaiGacohacaGGPbGaaiOBaiaaykW7caWG4baa % caGLiWoadaqhaaWcbaGaaGimaaqaamaalaaabaGaeqiWdahabaGaaG % OmaaaaaaGccqGHsisldaWdXbqaaiGacohacaGGPbGaaiOBaiaaykW7 % caWG4bGaaGPaVlaabsgacaWG4baaleaacaaIWaaabaWaaSaaaeaacq % aHapaCaeaacaaIYaaaaaqdcqGHRiI8aaaa!529D! I= \left. {x\sin \,x} \right|_0^{\frac{\pi }{2}} - \int\limits_0^{\frac{\pi }{2}} {\sin \,x\,{\rm{d}}x} \)\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeyypa0Zaaq % GaaeaadaqadaqaaiaadIhaciGGZbGaaiyAaiaac6gacaaMc8UaamiE % aiabgUcaRiGacogacaGGVbGaai4CaiaadIhaaiaawIcacaGLPaaaai % aawIa7amaaDaaaleaacaaIWaaabaWaaSaaaeaacqaHapaCaeaacaaI % Yaaaaaaaaaa!4898! = \left. {\left( {x\sin \,x + \cos x} \right)} \right|_0^{\frac{\pi }{2}}\) \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeyypa0ZaaS % aaaeaacqaHapaCaeaacaaIYaaaaiabgkHiTiaaigdaaaa!3B2B! = \frac{\pi }{2} - 1\)