Fourier transform of Bessel function

[bobred]

Homework Statement

Noting that J_0(k) is an even function of k, use the result of part (a) to
obtain the Fourier transform of the Bessel function J_0(x).

Homework Equations

In (a) I am asked to show that the Fourier transform of
f(x)=\dfrac{1}{\sqrt{1-x^{2}}}
is
\tilde{f}(k)=\sqrt{\pi/2}J_0(-k)
where
J_0(x)=\frac{1}{\pi}\int_{0}^{\pi} e^{i x \cos \theta}d \theta

The Attempt at a Solution

I have found the Fourier transform of f(x) using trig substitution I just can't see how to get the FT of J_0(x).
Any hints as to where I should begin?

 

[Fightfish]

Have you heard of the Fourier inversion theorem?
Make use of that, and the hint that question provided about the even nature of the Bessel function.

 

[bobred]

Hi
I went over my notes a few times and got it.
Thanks

 

[bobred]

Considering the second derivative of

show the Fourier transform of

is

I have done similar for

using rules for derivatives of Fourier transforms but can't see where to start, where the numerator

comes from.