f(x)= arctan(cosx) / arcsin(1−x2√) f′(0)=?
Or maybe write the equation without latex? because some latex doesn't seem to show and most latex under square roots don't show here. I tried it before.
If @OP didn't use latex, then I guess the equation would be: f(x) = arctan(cosx)/arcsin(1-2xsqrtf'(0)