Prove that if $f(n) \in O(g(n))$ then $g(n) \in \Omega(f(n))$.
So I know that
$$O(g(n)) \Rightarrow f(n) \leq c\cdot g(n)$$
and that
$$\Omega(g(n)) \Rightarrow f(n) \geq c\cdot g(n)$$
but how do you use these to do the above proof?
Prove that if $f(n) \in O(g(n))$ then $g(n) \in \Omega(f(n))$.
So I know that
$$O(g(n)) \Rightarrow f(n) \leq c\cdot g(n)$$
and that
$$\Omega(g(n)) \Rightarrow f(n) \geq c\cdot g(n)$$
but how do you use these to do the above proof?