How do you graph the system of polar equations to solve r=1+cosθ and r=1cosθ?

1 Answer
Nov 14, 2016

graph{x^2+y^2-sqrt(x^2+y^2)-x=0 [-10, 10, -5, 5]} Common points are at (r,θ)=(1,±π2)

graph{(x^2+y^2+x)^2-x^2-y^2=0 [-10, 10, -5, 5]}

Explanation:

Using the cartesian equivalents (x2+y2±x)x2+y2=0

for r=1±cosθ, the graphs are obtained. The graphs are

are symmetrically opposite, about the y-axis .

By this symmetry, the two meet on the vertical axis, given in

halves, by θ=±π2, wherein r=1, at both the common points.

Algebraically adding and subtracting r=1±cosθ, the solutions

(r,θ)=(1,±π2) can be obtained.we y