(2013)函數(shù)的極值可疑點(diǎn)的個數(shù)是:()
A.0 B.1 C.2 D.3
(2013)設(shè),則,f(x)在點(diǎn)x=1處:()
A.不連續(xù) B.連續(xù)但左、右導(dǎo)數(shù)不存在 C.連續(xù)但不可導(dǎo) D.可導(dǎo)
A.∣A+B∣≤∣A∣+∣B∣ B.(AB)T=ATBT C.(A+B)2=A2+2AB+B2 D.∣AB∣=∣BA∣