A.0<dy<△y. B.0<△y<dy. C.△y<dy<0. D.dy<△y<0.
单项选择题设f(x)连续,令,则F(x)为()
A.2xf(x-x2)-f(0) B.f(x-x2)-f(0) C.(2x-1)f(x-x2) D.2x[f(x-x2)-f(0)]
单项选择题设f(x)连续,若=()
A.1 B.-1 C.3 D.-3