Cho tích phân \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamysaiabg2 % da9maapehabaWaaeWaaeaacaWG4bGaeyOeI0IaaGymaaGaayjkaiaa % wMcaaiGacohacaGGPbGaaiOBaiaaikdacaWG4bGaamizaiaadIhaaS % qaaiaaicdaaeaadaWcaaqaaiabec8aWbqaaiaaisdaaaaaniabgUIi % Ydaaaa!481B! I = \int\limits_0^{\frac{\pi }{4}} {\left( {x - 1} \right)\sin 2xdx} \). Tìm đẳng thức đúng
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Lời giải:
Báo sai\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaiqaaqaabe % qaaiaadwhacqGH9aqpcaWG4bGaeyOeI0IaaGymaaqaaiaadsgacaWG % 2bGaeyypa0Jaci4CaiaacMgacaGGUbGaaGOmaiaadIhacaWGKbGaam % iEaaaacaGL7baacqGHshI3daGabaabaeqabaGaamizaiaadwhacqGH % 9aqpcaWGKbGaamiEaaqaaiaadAhacqGH9aqpcqGHsisldaWcaaqaai % aaigdaaeaacaaIYaaaaiGacogacaGGVbGaai4CaiaaikdacaWG4baa % aiaawUhaaaaa!5669! \left\{ \begin{array}{l} u = x - 1\\ dv = \sin 2xdx \end{array} \right. \Rightarrow \left\{ \begin{array}{l} du = dx\\ v = - \frac{1}{2}\cos 2x \end{array} \right.\)
\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamysaiabg2 % da9iabgkHiTmaalaaabaGaaGymaaqaaiaaikdaaaWaaeWaaeaacaWG % 4bGaeyOeI0IaaGymaaGaayjkaiaawMcaaiGacogacaGGVbGaai4Cai % aaikdacaWG4bWaaqqaaqaabeqaamaalaaabaGaeqiWdahabaGaaGin % aaaaaeaacaaIWaaaaiaawEa7aiabgUcaRmaalaaabaGaaGymaaqaai % aaikdaaaWaa8qCaeaaciGGJbGaai4BaiaacohacaaIYaGaamiEaiaa % dsgacaWG4baaleaacaaIWaaabaWaaSaaaeaacqaHapaCaeaacaaI0a % aaaaqdcqGHRiI8aaaa!565F! I = - \frac{1}{2}\left( {x - 1} \right)\cos 2x\left| \begin{array}{l} \frac{\pi }{4}\\ 0 \end{array} \right. + \frac{1}{2}\int\limits_0^{\frac{\pi }{4}} {\cos 2xdx} \)