Tính \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamysaiabg2 % da9maapehabaGaamiEaiaabwgadaahaaWcbeqaaiaadIhaaaaabaGa % aGymaaqaaiaaikdaa0Gaey4kIipakiaaykW7caqGKbGaamiEaaaa!4225! I = \int\limits_1^2 {x{{\rm{e}}^x}} \,{\rm{d}}x\)
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Lời giải:
Báo saiĐặt \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaiqaaqaabe % qaaiaadwhacqGH9aqpcaWG4baabaGaaGPaVlaabsgacaWG2bGaeyyp % a0JaaiyzamaaCaaaleqabaGaamiEaaaakiaaykW7caqGKbGaamiEaa % aacaGL7baaaaa!4411! \left\{ \begin{array}{l} u = x\\ \,{\rm{d}}v = {e^x}\,{\rm{d}}x \end{array} \right.\)\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeyO0H49aai % qaaqaabeqaaiaabsgacaWG1bGaeyypa0JaaGPaVlaabsgacaWG4baa % baGaamODaiabg2da9iaacwgadaahaaWcbeqaaiaadIhaaaaaaOGaay % 5Eaaaaaa!43E6! \Rightarrow \left\{ \begin{array}{l} {\rm{d}}u = \,{\rm{d}}x\\ v = {e^x} \end{array} \right.\)
Khi đó \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamysaiabg2 % da9maaeiaabaGaamiEaiaacwgadaahaaWcbeqaaiaadIhaaaaakiaa % wIa7amaaDaaaleaacaaIXaaabaGaaGOmaaaakiabgkHiTmaapehaba % GaaiyzamaaCaaaleqabaGaamiEaaaaaeaacaaIXaaabaGaaGOmaaqd % cqGHRiI8aOGaaGPaVlaabsgacaWG4baaaa!4874! I = \left. {x{e^x}} \right|_1^2 - \int\limits_1^2 {{e^x}} \,{\rm{d}}x\)\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeyypa0JaaG % OmaiaacwgadaahaaWcbeqaaiaaikdaaaGccqGHsislcaGGLbGaeyOe % I0YaaqGaaeaacaGGLbWaaWbaaSqabeaacaWG4baaaaGccaGLiWoada % qhaaWcbaGaaGymaaqaaiaaikdaaaaaaa!41AC! = 2{e^2} - e - \left. {{e^x}} \right|_1^2\)\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeyypa0JaaG % OmaiaacwgadaahaaWcbeqaaiaaikdaaaGccqGHsislcaGGLbGaeyOe % I0IaaiyzamaaCaaaleqabaGaaGOmaaaakiabgUcaRiaacwgacqGH9a % qpcaGGLbWaaWbaaSqabeaacaaIYaaaaaaa!42D4! = 2{e^2} - e - {e^2} + e = {e^2}\)