Tính \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOsaiabg2 % da9maapehabaGaamiEaiGacohacaGGPbGaaiOBaiaadIhacaaMc8Ua % aeizaiaadIhaaSqaaiaaicdaaeaacaqGapaaniabgUIiYdaaaa!4473! J = \int\limits_0^{\rm{\pi }} {x\sin x\,{\rm{d}}x} \)
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Lời giải:
Báo saiĐặt \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaiqaaeaafa % qabeGabaaabaGaamyDaiabg2da9iaadIhacaqGGaGaaeiiaiaabcca % caqGGaGaaeiiaiaabccacaqGGaGaaeiiaiaabccacaqGGaaabaGaae % izaiaadAhacqGH9aqpciGGZbGaaiyAaiaac6gacaWG4bGaaGPaVlaa % bsgacaWG4baaaaGaay5Eaaaaaa!4AA2! \left\{ {\begin{array}{*{20}{c}} {u = x{\rm{ }}}\\ {{\rm{d}}v = \sin x\,{\rm{d}}x} \end{array}} \right.\)\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeyO0H49aai % qaaeaafaqabeGabaaabaGaaeizaiaadwhacqGH9aqpcaqGKbGaamiE % aiaabccacaqGGaGaaeiiaiaabccaaeaacaWG2bGaeyypa0JaeyOeI0 % Iaci4yaiaac+gacaGGZbGaamiEaaaaaiaawUhaaaaa!478D! \Rightarrow \left\{ {\begin{array}{*{20}{c}} {{\rm{d}}u = {\rm{d}}x{\rm{ }}}\\ {v = - \cos x} \end{array}} \right.\)
Ta có \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeyypa0Zaaq % GaaeaacqGHsislcaWG4bGaci4yaiaac+gacaGGZbGaamiEaaGaayjc % SdWaa0baaSqaaiaaicdaaeaacaqGapaaaOGaey4kaSYaa8qCaeaaci % GGJbGaai4BaiaacohacaWG4bGaaGPaVlaabsgacaWG4baaleaacaaI % WaaabaGaaeiWdaqdcqGHRiI8aaaa!4D0B! = \left. { - x\cos x} \right|_0^{\rm{\pi }} + \int\limits_0^{\rm{\pi }} {\cos x\,{\rm{d}}x} \)\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeyypa0Jaae % iWdiabgkHiTmaaeiaabaGaci4CaiaacMgacaGGUbGaamiEaaGaayjc % SdWaa0baaSqaaiaaicdaaeaacaqGapaaaaaa!40C5! = {\rm{\pi }} - \left. {\sin x} \right|_0^{\rm{\pi }} = \pi\)