I can't find the answer to this problem. It just says to find this double integral converting it to polar integral.
$$\int_{0}^{1} \int_{-{y}/{3}}^{{y}/{3}} \frac{y}{\sqrt{x^2+y^2}}\ dx\ dy$$
I know the first is $0$ to $π/2$ but I can't find the solution for the second: $-y/3$ and $y/3$.
HINT: Here is a graph of the lines $y = 1$ (blue), $x = -y/3$ (green), and $x = y/3$ (yellow):
Based on this graph, what is the range of $\theta$ values that you need to integrate over? (It's not 0 to $\pi/2$.) For a given $\theta$ value, what is the range of $r$ values you need to integrate over?