#### Answer

Domain$= (-\infty,\infty)$
Range= $[2,4]$

#### Work Step by Step

The cosine is defined for all reals, so
Domain = $\mathbb{R}= (-\infty,\infty)$
Range:
Minimum of cosine is $-1$,
so the minimum of F is $3-1=2$
Maximum of cosine is $+1$,
so the minimum of F is $3+1=4$
Range= $[2,4]$