Hello everyone! i'm very confused on why i'm not getting this answer right, even the TI-83 says my answer is correct.
The directions say,
Consider the polar curve r = 2 sin(3x) for [0,PI]. Find the region inside the curve, using the calculator, i found the area as 1.3333, which is 4/3. I also found 4/3 by taking the definate integral from 0 to PI.

A = definate integral from 0 to PI (2*sin(3*x));
A = 2/3* definate integral from 0 to PI sin(u) du
2/3[-cos(3*x)] from 0 to PI.

i used u substitution u = 3x, du = 3dx, 1/3du = dx;

The only answers to choose from are:
2PI, PI, 3PI, 4PI, 5PI

and 4/3 isn't any of them!
any idea's?