How do you convert the cartesian coordinate (2, -4) into polar coordinates? Precalculus Polar Coordinates Converting Coordinates from Rectangular to Polar 1 Answer Bdub Sep 11, 2017 see below Explanation: Use the formulas #x^2 + y^2 =r^2# and #tan theta =y/x# #r^2=(2)^2+(-4)^2=4+16=20# #r=sqrt20 = 2sqrt5~~4.472# #tan theta = -4/2# #theta=tan^-1 -2# #theta ~~-1.107# #:.(r,theta)~~ (4.472, -1.107)# Answer link Related questions What are the polar coordinates of #(0, -2)#? What are the polar coordinates of #(-4, 0)#? What are the polar coordinates of #(3, 4)#? What are the polar coordinates of #(-2,0)#? How do I convert Cartesian coordinates to polar coordinates? How do I find the polar form of #a+bi#? How do I find the polar form of #3sqrt2 - 3sqrt2i#? How do you change (4, -1) from rectangular to cylindrical coordinates between [0, 2π)? How do you change (0,3,-3) from rectangular to spherical coordinates? How do you find the rectangular coordinates if you given the cylindrical coordinate #(5, pi/6, 5)#? See all questions in Converting Coordinates from Rectangular to Polar Impact of this question 4047 views around the world You can reuse this answer Creative Commons License