Question

How do you graph `r=2costheta`?

Answer 1

Draw the circle with center at #(r, theta)=(1,0) and radius 1 unit

Explanation:

Referred to (a, 0) as center and radius = a, the equation of the circle is `r = 2a cos theta`.

If O is the pole, OA = 2a is the diameter through O and P is any point `(r, theta)` on the circle, `OP = r, angleAOP=theta. OP = OA cos theta.. So, r = 2a cos theta`