D and math, can you isolate this ?

[Basile B. via Digitalmars-d-learn]

On Tuesday, 20 September 2016 at 12:35:18 UTC, Basile B. wrote:
> The problem is here:
> https://github.com/BBasile/iz/blob/master/import/iz/math.d#L849
> - f(x,c) = 1.0 - pow(1.0 - pow(x, 2.0/c), c * 0.5);
> - c(f0.5)) = ?
>
> Which means that I ask you if you can isolate c for
>
> y = 1.0 - pow(1.0 - pow(0.5, 2.0/c), c * 0.5);
>
> y is always f(0.5,c)

Forget to say yesterday that actually the original equation is

x = pow(cos(angle), 0.25*c);
y = pow(sin(angle), 0.25*c);

But I couldn't use this form.