(2013)設,則,f(x)在點x=1處:()
A.不連續(xù) B.連續(xù)但左、右導數不存在 C.連續(xù)但不可導 D.可導
A.∣A+B∣≤∣A∣+∣B∣ B.(AB)T=ATBT C.(A+B)2=A2+2AB+B2 D.∣AB∣=∣BA∣
已知齊次線性方程有非零解,則常數λ可取為()
A.2,5,8 B.-2,-5,-8 C.-2,5,8 D.2,-5,-8