f(x)={[3/(5-x)]+x平方/5}求导
问题描述:
f(x)={[3/(5-x)]+x平方/5}求导
答
f(x)=3/(5-x)+x²/5
f'(x)=[3/(5-x)]'+[x²/5]'
=[3'×(5-x)-3×(5-x)']/(5-x)²+2x/5
=-3×(-1)/(5-x)²+2x/5
=3/(5-x)²+2x/5