Double integrals in polar

Let $R$R be the region inside the polar curves $r = \cos(\theta)$r, equals, cosine, left parenthesis, theta, right parenthesis and $r = -\sin(\theta)$r, equals, minus, sine, left parenthesis, theta, right parenthesis, where $-\dfrac{\pi}{2} < \theta < -\dfrac{\pi}{4}$minus, start fraction, pi, divided by, 2, end fraction, is less than, theta, is less than, minus, start fraction, pi, divided by, 4, end fraction.

Let $f(x, y) = x^2 + y^2$f, left parenthesis, x, comma, y, right parenthesis, equals, x, squared, plus, y, squared.