The letters x and y represent rectangular coordinates Write

The letters x and y represent rectangular coordinates. Write the given equation using polar coordinates (r, theta) x^2 = 9y Select the equation in polar coordinates. 9r cos theta - sin0 = 0 r^2 cos^2 theta -9r sin theta = 0 9r cos theta - r^2 sin^2 theta^2 = 0 r^2 cos theta - 9r sin theta = 0

Solution

x² = 9y

Substitute for x: r*cos(), and for y: r*sin(). You get

r² cos² = 9 r sin

Therefore, r² cos² - 9 r sin = 0