Hi, just wonderin if I could have some help with these two questions: each of them asks to find the domain and the range using calculus techniques, and as I am reveiwing this after doing this 12 weeks ago, I am a bit hazy as to what's required.

(a)f(x)=cos sqrt(e^x-1)

(b) g(x)=1//(x^2+1)

if anyone could help and explain fully, that would be greatly appreciated