Cho hàm số f(x) xác định trên R\{1} bởi \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamOzamaabm % aabaGaamiEaaGaayjkaiaawMcaaiabg2da9maalaaabaGaaGOmaiaa % dIhaaeaacaWG4bGaeyOeI0IaaGymaaaaaaa!3ED9! f\left( x \right) = \frac{{2x}}{{x - 1}}\). Giá trị của f’(-1) bằng:
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Lời giải:
Báo sai\(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGabmOzayaafa % WaaeWaaeaacaWG4baacaGLOaGaayzkaaGaeyypa0ZaaSaaaeaacaaI % YaWaaeWaaeaacaWG4bGaeyOeI0IaaGymaaGaayjkaiaawMcaaiabgk % HiTiaaikdacaWG4baabaWaaeWaaeaacaWG4bGaeyOeI0IaaGymaaGa % ayjkaiaawMcaamaaCaaaleqabaaeaaaaaaaaa8qacaaIYaaaaaaak8 % aacqGH9aqpdaWcaaqaaiabgkHiTiaaikdaaeaadaqadaqaaiaadIha % cqGHsislcaaIXaaacaGLOaGaayzkaaWaaWbaaSqabeaapeGaaGOmaa % aaaaaaaa!4F4D! f'\left( x \right) = \frac{{2\left( {x - 1} \right) - 2x}}{{{{\left( {x - 1} \right)}^2}}} = \frac{{ - 2}}{{{{\left( {x - 1} \right)}^2}}}\) \(% MathType!MTEF!2!1!+- % feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9 % vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x % fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaaccaGae8N0H4 % TabmOzayaafaWaaeWaaeaacqGHsislcaaIXaaacaGLOaGaayzkaaGa % eyypa0JaeyOeI0YaaSaaaeaacaaIXaaabaGaaGOmaaaaaaa!3FF6! \Rightarrow f'\left( { - 1} \right) = - \frac{1}{2}\)