Tính \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamysaiabg2 % da9maapehabaWaaSaaaeaacaWG4bWaaWbaaSqabeaacaaIYaGaaGim % aiaaigdacaaI4aaaaaGcbaGaaeyzamaaCaaaleqabaGaamiEaaaaki % abgUcaRiaaigdaaaGaaeizaiaadIhaaSqaaiabgkHiTiaaikdaaeaa % caaIYaaaniabgUIiYdaaaa!466A! I = \int\limits_{ - 2}^2 {\frac{{{x^{2018}}}}{{{{\rm{e}}^x} + 1}}{\rm{d}}x} \)
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Lời giải:
Báo sai\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamiEaiabg2 % da9iabgkHiTiaadshacqGHshI3caqGKbGaamiEaiabg2da9iabgkHi % TiaabsgacaWG0baaaa!41F1! x = - t \Rightarrow {\rm{d}}x = - {\rm{d}}t\); khi x = - 2 thì t = 2 khi x = 2 thì t = -2
\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamysaiabg2 % da9maapehabaWaaSaaaeaacaWG4bWaaWbaaSqabeaacaaIYaGaaGim % aiaaigdacaaI4aaaaaGcbaGaaeyzamaaCaaaleqabaGaamiEaaaaki % abgUcaRiaaigdaaaGaaeizaiaadIhaaSqaaiabgkHiTiaaikdaaeaa % caaIYaaaniabgUIiYdGccqGH9aqpdaWdXbqaamaalaaabaWaaeWaae % aacqGHsislcaWG0baacaGLOaGaayzkaaWaaWbaaSqabeaacaaIYaGa % aGimaiaaigdacaaI4aaaaaGcbaGaaeyzamaaCaaaleqabaGaeyOeI0 % IaamiDaaaakiabgUcaRiaaigdaaaGaaeizaiaadshaaSqaaiabgkHi % TiaaikdaaeaacaaIYaaaniabgUIiYdGccqGH9aqpdaWdXbqaamaala % aabaGaamiDamaaCaaaleqabaGaaGOmaiaaicdacaaIXaGaaGioaaaa % kiaac6cacaqGLbWaaWbaaSqabeaacaWG0baaaaGcbaGaaeyzamaaCa % aaleqabaGaamiDaaaakiabgUcaRiaaigdaaaGaaeizaiaadshaaSqa % aiabgkHiTiaaikdaaeaacaaIYaaaniabgUIiYdaaaa!6BE3! I = \int\limits_{ - 2}^2 {\frac{{{x^{2018}}}}{{{{\rm{e}}^x} + 1}}{\rm{d}}x} = \int\limits_{ - 2}^2 {\frac{{{{\left( { - t} \right)}^{2018}}}}{{{{\rm{e}}^{ - t}} + 1}}{\rm{d}}t} = \int\limits_{ - 2}^2 {\frac{{{t^{2018}}.{{\rm{e}}^t}}}{{{{\rm{e}}^t} + 1}}{\rm{d}}t} \)\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeyO0H4TaaG % OmaiaadMeacqGH9aqpdaWdXbqaaiaadshadaahaaWcbeqaaiaaikda % caaIWaGaaGymaiaaiIdaaaGccaqGKbGaamiDaaWcbaGaeyOeI0IaaG % Omaaqaaiaaikdaa0Gaey4kIipaaaa!45B2! \Rightarrow 2I = \int\limits_{ - 2}^2 {{t^{2018}}{\rm{d}}t} \)\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeyypa0Zaaq % GaaeaadaWcaaqaaiaadshadaahaaWcbeqaaiaaikdacaaIWaGaaGym % aiaaiMdaaaaakeaacaaIYaGaaGimaiaaigdacaaI5aaaaaGaayjcSd % Waa0baaSqaaiabgkHiTiaaikdaaeaacaaIYaaaaaaa!424A! = \left. {\frac{{{t^{2019}}}}{{2019}}} \right|_{ - 2}^2\) \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeyypa0ZaaS % aaaeaacaaIYaGaaiOlaiaaikdadaahaaWcbeqaaiaaikdacaaIWaGa % aGymaiaaiMdaaaaakeaacaaIYaGaaGimaiaaigdacaaI5aaaaaaa!3F53! = \frac{{{{2.2}^{2019}}}}{{2019}}\)
\( \Rightarrow I = \frac{{{2^{2019}}}}{{2019}}\)