Question

AP Calculus (See Picture to Help Explain Steps)

Answer 1

How do they get pi/6 out

Answer 2

On Step One is where it is confusing

Answer 3

Since you can always multiply an equation by 1, they're multiplying by
\[1=\frac{\frac{\pi}{6}}{\frac{\pi}{6}}=\frac{6}{\pi} \frac{\pi}{6} \]
to make the integral easier.