The inverse Fourier transform is defined as:
$$\mathcal{F}^{-1}[g](x) = \frac{1}{\sqrt{2 \pi}} \int_{-\infty}^{\infty} g(k) e^{i k x} d k$$
I can't get an inverse Fourier Transform to
Q1: $$g(k)=\cos (\sqrt{ k^2 d -a^2 })$$ Q2:
$$g(k)=\frac{1}{ \sqrt{ k^2 d -a^2 }}\sin (\sqrt{ k^2 d -a^2 })$$
I would really appreciate some any help .