What is the polar form of ( 11,-9 )?

1 Answer
Mar 22, 2018

The polar form of the coordinate pair (11, -9) is (sqrt(202), -39.289).

Explanation:

The polar form of a coordinate pair (x, y) is (r, theta).
To find r, we use the formula r^2 = x^2+y^2.
r^2 = 11^2 + (-9)^2
r^2 = 121 + 81
r^2 = 202
r = sqrt(202)
r ~~ 14.21
To find theta, we use the formula y/x = tan(theta).
(-9)/11 = tan(theta)
theta = tan^-1((-9)/11)
theta ~~ tan^-1(0.818182)
theta ~~ -39.289407