Kết quả của \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGacaGaaiaabeqaamaabaabaaGcbaGaamysaiabg2 % da9maapeaabaGaamiEaiaadwgadaahaaWcbeqaaiaadIhaaaaabeqa % b0Gaey4kIipakiaabsgacaWG4baaaa!3EB4! I = \int {x{e^x}} {\rm{d}}x\) là
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Lời giải:
Báo saiCách 1: Sử dụng tích phân từng phần ta có: \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGacaGaaiaabeqaamaabaabaaGcbaGaamysaiabg2 % da9maapeaabaGaamiEaiaadwgadaahaaWcbeqaaiaadIhaaaaabeqa % b0Gaey4kIipakiaabsgacaWG4bGaeyypa0Zaa8qaaeaacaWG4baale % qabeqdcqGHRiI8aOGaaGPaVlaabsgacaWGLbWaaWbaaSqabeaacaWG % 4baaaOGaeyypa0JaamiEaiaadwgadaahaaWcbeqaaiaadIhaaaGccq % GHsisldaWdbaqaaiaadwgadaahaaWcbeqaaiaadIhaaaaabeqab0Ga % ey4kIipakiaabsgacaWG4bGaeyypa0JaamiEaiaadwgadaahaaWcbe % qaaiaadIhaaaGccqGHsislcaWGLbWaaWbaaSqabeaacaWG4baaaOGa % ey4kaSIaam4qaiaac6caaaa!5BD4! I = \int {x{e^x}} {\rm{d}}x = \int x \,{\rm{d}}{e^x} = x{e^x} - \int {{e^x}} {\rm{d}}x = x{e^x} - {e^x} + C.\)
Cách 2: Ta có: \(% MathType!MTEF!2!1!+- % feaahqart1ev3aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGacaGaaiaabeqaamaabaabaaGcbaGabmysayaafa % Gaeyypa0ZaaeWaaeaacaWG4bGaamyzamaaCaaaleqabaGaamiEaaaa % kiabgkHiTiaadwgadaahaaWcbeqaaiaadIhaaaGccqGHRaWkcaWGdb % aacaGLOaGaayzkaaWaaWbaaSqabeaakiadacUHYaIOaaGaeyypa0Ja % amyzamaaCaaaleqabaGaamiEaaaakiabgUcaRiaadIhacaWGLbWaaW % baaSqabeaacaWG4baaaOGaeyOeI0IaamyzamaaCaaaleqabaGaamiE % aaaakiabg2da9iaadIhacaWGLbWaaWbaaSqabeaacaWG4baaaOGaai % Olaaaa!5348! I' = {\left( {x{e^x} - {e^x} + C} \right)^\prime } = {e^x} + x{e^x} - {e^x} = x{e^x}.\)
Đề thi thử tốt nghiệp THPT QG môn Toán năm 2020
Tuyển chọn số 2