Cho hàm số \(% MathType!MTEF!2!1!+-
% feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn
% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr
% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9
% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x
% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaamyEaiabg2
% da9iaadAgadaqadaqaaiaadIhaaiaawIcacaGLPaaacqGH9aqpdaWc
% aaqaaiabgkHiTiaadIhadaahaaWcbeqaaiaaikdaaaGccqGHRaWkca
% WG4bGaey4kaSIaaGOmaaqaaiaadIhacqGHsislcaaIXaaaaaaa!457E!
y = f\left( x \right) = \frac{{ - {x^2} + x + 2}}{{x - 1}}\). Xét hai mệnh đề :
\(% MathType!MTEF!2!1!+-
% feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn
% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr
% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9
% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x
% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaeWaaeaaca
% WGjbaacaGLOaGaayzkaaGaaiOoaiqadMhagaqbaiabg2da9iqadAga
% gaqbamaabmaabaGaamiEaaGaayjkaiaawMcaaaaa!3E96!
\left( I \right):y' = f'\left( x \right)\) \(% MathType!MTEF!2!1!+-
% feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn
% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr
% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9
% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x
% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeyypa0Jaey
% OeI0IaaGymaiabgkHiTmaalaaabaGaaGOmaaqaaiaacIcacaWG4bGa
% eyOeI0IaaGymaiaacMcadaahaaWcbeqaaiaaikdaaaaaaOGaeyipaW
% JaaGimaiaacYcacqGHaiIicaWG4bGaeyiyIKRaaGymaaaa!4609!
= - 1 - \frac{2}{{{{(x - 1)}^2}}} < 0,\forall x \ne 1\)
\(% MathType!MTEF!2!1!+-
% feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn
% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr
% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9
% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x
% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaWaaeWaaeaaca
% WGjbGaamysaaGaayjkaiaawMcaaiaacQdaceWG5bGbayaacqGH9aqp
% ceWGMbGbayaadaqadaqaaiaadIhaaiaawIcacaGLPaaaaaa!3F66!
\left( {II} \right):y'' = f''\left( x \right)\) \(% MathType!MTEF!2!1!+-
% feaahqart1ev3aqatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn
% hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr
% 4rNCHbGeaGqiVu0Je9sqqrpepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9
% vqaqpepm0xbba9pwe9Q8fs0-yqaqpepae9pg0FirpepeKkFr0xfr-x
% fr-xb9adbaqaaeGaciGaaiaabeqaamaabaabaaGcbaGaeyypa0ZaaS
% aaaeaacaaI0aaabaGaaiikaiaadIhacqGHsislcaaIXaGaaiykamaa
% CaaaleqabaGaaGOmaaaaaaGccqGH+aGpcaaIWaGaaiilaiabgcGiIi
% aadIhacqGHGjsUcaaIXaaaaa!437A!
= \frac{4}{{{{(x - 1)}^2}}} > 0,\forall x \ne 1\)
Mệnh đề nào đúng