Question

函数f（x）=（根号x^2+1）-x用导数法化简,怎么变呢?

Answer 1

是倒数法吧?

f(x)=√(x²+1)-x

=[√(x²+1)-x][√(x²+1)+x]/[√(x²+1)+x]

=1/[√(x²+1)+x]