I have the series $1+3+9+27+... + 3^n$ . I need to find the Big O solution.
What I have tried.
The above series is a Geometric Progression with r=3. SO the sum would be.
$ [1* 3^{n+1} - 1]/2 $
How do I get the Big Oh notation of the above expression.
You take the most significant term, which is $3^{n+1}/2$. That turns out to be $3/2 \cdot 3^n$, so the expression is $O(3^n)$.