Convert loop into mathematical equation

Question

How would I represent this for loop in a mathematical equation?

double n = 1;
    double x = Math.pow(3, n);
    for(double i = 0; i < n; i++){
        x = x + Math.pow(3, i);
    }

Sorry wrote it in Java in a hurry.

score 0 · Accepted Answer · answered Feb 08 '15 at 08:56

0

for loop can be simplifed to

x= (pow(3,n)-1)/2

answered Feb 08 '15 at 08:56

Luka Rahne

Hey, Thanks so much! Would you mind explaining how you got there? – MarkTHarris Feb 08 '15 at 09:03
It is sum of geometric series. – Luka Rahne Feb 08 '15 at 09:06
1

But not with the initialization of x as given! This would be (pow(3,n+1)-1)/2. – laune Feb 08 '15 at 10:06

1 Answers1