Please answer d, e, and f.

Thank you!!

3-4 Asymptotic notation properties Let f(n) and g(n) be asymptotically positive functions. Prove or disprove each of the following conjectures. d. f(n)=O(g(n)) implies 2f(n)=O(2g(n)). e. f(n)=O((f(n))2). f. f(n)=O(g(n)) implies g(n)=(f(n))