Polar and Rectangular

Instead of using (x,y), you use (r, θ).

To convert from polar to rectangular, use the following formulas: 

x=rcosθ

y=rsinθ

To convert from rectangular to polar, use the following formulas:

r=√x^2+y^2

θ=tan^-1(y/x)

Give the polar coordinates for the point (0,5)

r=√0^2+5^2

 =√25

 =5

θ=tan^-1(5/0)

  =undefined