Prove that f(n) = 2010n^2 + 1388n belongs to o(n^3)
My work so far: This must be true: for ALL constats c>0, there exists a constant n0>0 such that 0<=2010n^2 + 1388n<=cn^3 for all n>n0
By simplifying we get: c>= 2010/n + 1388/n^2
Not sure what to do next to find n0.
You might have an easier time with an equivalent definition of little-o notation: we say that f = o(g) if
limn → ∞ f(n) / g(n) = 0
In your case, this means that you'd prove that
limn → ∞ (2010n2 + 1388n) / n3 = 0
To see this, note that
limn → ∞ (2010n2 + 1388n) / n3
= limn → ∞ (2010n2 / n3) + (1388n) / n3
= limn → ∞ (2010 / n) + (1388 / n2)
= limn → ∞ (2010 / n) + limn → ∞ (1388 / n2)
= 0 + 0
= 0
Hope this helps!