I am trying to justify the big-O order of a runtime complexity by finding a $c$ and $n_0$ that hold for it. Does the left side of the justification need to be one or higher, or can it be any value so long as it is a real number and less than the right side? For instance, is the following valid: $$n^2/4 + 1/2 \leq c\cdot n^2\,,$$
when $c= 1$ and $n=1$: $$3/4 \leq 1\,.$$