As the title suggests, I'm doing a Laplace transform problem using the $t$-shift theorem, and I've almost got it, I just can't work out how to transform $\cos(t)$ into a function of $(t-2)$, I saw a trig identity
$\cos(x)\cos(y) = \frac{1}{2} [\cos(x - y) + \cos(x + y)]$
But I can't quite work out how to re-arrange it, any help much appreciated.
Thanks.