Question

How do you convert `r = 2cosθ` into rectangular form?

Answer 1

`x^2-2x+y^2=0`

`(x-1)^2+y^2=1`

Explanation:

Multiply both sides by `r` to get `r^2=2rcostheta`

`r^2=x^2+y^2`
`2rcostheta=2x`

`x^2+y^2=2x`

`x^2-2x+y^2=0`

`(x-1)^2+y^2=1`