Relationship between decay of the Fourier transform and the smoothness of $f$

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I'm doing the following exercise

$a)$ Calculate the Fourier transform of the function $f(x) = e^{-|x|}, \ x \in \mathbb{R}$

Then answer which I calculated is that $\mathscr{F}(f)(k) = \frac{2}{1+k^2} $

$b)$ Is the relationship between decay of the Fourier transform as $k \to \infty$ and the smoothness of $f$ reminiscent of what you know about fourier series?

I need help with $b)$ what are they aiming at?

I have concluded that since $f'$ is not continuous $f \in C^0$ and the Fourier transform decays as $\frac{1}{k^2}$