Question

How do you convert the Cartesian coordinates (3,-9) to polar coordinates?

Answer 1

Refer to explanation

Explanation:

To convert from from Cartesian Coordinates `(x,y)` to Polar Coordinates `(r,θ)` we use the following formulas

`r=sqrt(x^2+y^2)` and `θ=arctan(y/x)`

Hence for `(3,-9)` we have that

`r=sqrt((3)^2+(-9^2))=sqrt(90)=3sqrt(10)` and

`θ=arctan (-3)=-arctan(3)=-71.57^o`