Question

高二导数问题：已知函数y=f(x)=1/根号下x,则f’(1)=?

Answer 1

求导的时候,如果遇到根号啊,倒数啊这些个东西,尽量的都化为指数去做,一般都会方便许多.熟记这两个公式:

根号x = x^(1/2)

1/x = x^(-1)

f(x) = 1/根号x = 1/(x^(1/2)) = x^(-1/2)

f'(x) = (-1/2)x^(-3/2)

f'(1) = -1/2