設(shè)函數(shù)f(x)有連續(xù)的導(dǎo)數(shù),f(0)=0,f′(0)≠0,當(dāng)x→0時(shí),F(xiàn)(x)=(sin2x-sin2t)f(t)dt與xk為同階無窮小,則k為()
A.1 B.2 C.3 D.4
設(shè)M=cos4xdx,N=(sin3x+cos4x)dx,P=(x2sin3x-cos4x)dx,則有()
A.N<P<M B.M<P<N C.N<M<P D.P<M<N
設(shè)F(x)=esintsintdt,則F(x)()
A.為正常數(shù); B.為負(fù)常數(shù); C.恒為零; D.不是常數(shù).