Using the basic definition of theta notation prove that $\max(f(n), g(n)) = \Theta(f(n) + g(n))$
I came across two answer to this question on this website but the answers weren't clear to me. Would you mind to elaborate how this can be proven? I am first year student of computer sciences. Thank you!
Edit:
What exactly does $\max(f(n), g(n))$ return?