How do you convert (11,-9)(11,9) into polar coordinates?

1 Answer
May 6, 2018

(sqrt202,tan^-1(-9/11)+2pi) or (14.2,5.60^c)(202,tan1(911)+2π)or(14.2,5.60c)

Explanation:

(x,y)->(r,theta);(r,theta)=(sqrt(x^2+y^2),tan^-1(y/x))(x,y)(r,θ);(r,θ)=(x2+y2,tan1(yx))

r=sqrt(x^2+y^2)=sqrt(11^2+(-9)^2)=sqrt(121+81)=sqrt202~~14.2r=x2+y2=112+(9)2=121+81=20214.2

theta=tan^-1(-9/11)θ=tan1(911)

However, (11,-9)(11,9) is in quadrant 4, and so we must add 2pi2π to our answer.

theta=tan^-1(-9/11)+2pi ~~5.60^cθ=tan1(911)+2π5.60c

(sqrt202,tan^-1(-9/11)+2pi) or (14.2,5.60^c)(202,tan1(911)+2π)or(14.2,5.60c)