Question

How do you convert `r = 4` into cartesian form?

Answer 1

`x^2+y^2=16`

Explanation:

The relation between polar coordinates `(r,theta)` and Cartesian coordinates `(x,y)` is given by

`x=rcostheta`, `y=rsintheta`, `r^2=x^2+y^2`.

Using them `r=4` is `r^2=16` or `x^2+y^2=16`

which is the equation of circle with radius `4`.