設(shè)(d/dx)f(x)=g(x),h(x)=x2,則(d/dx)f[h(x)]等于:()
A.g(x2) B.2xg(x) C.x2g(x2) D.2xg(x2)
設(shè)y=cos(arcsinx/2),則y′(/2)的值等于()
A.-1/2 B.-/2 C.1/2 D./2
設(shè),則k的值是:()
A.1/6 B.1 C.1/4 D.1/3