[R] How to find a uniroot of a deriv function

[Patrick Wang]

Hi, All

Assume I have function x^2-1, I tried to find the root of its derivative
2*x = 0.

I run the command below but it return 1, root of the original function.
Does anyone know how to get the root of the derived function?

Thanks
pat
========================================
func = deriv(parse(text="x^2-1"), "x", func=TRUE)
uniroot(func, interval=(-0.1,1.1), tol=1e-6)
========================
$root
[1] 1

$f.root
[1] -1.709702e-07
attr(,"gradient")
     x
[1,] 2