# How do you convert #8 - 15i# to polar form?

##### 1 Answer

May 6, 2017

#### Explanation:

#"to convert from "color(blue)"cartesian to polar form"#

#"that is " (x,y)to(r,theta)" where"#

#• r=sqrt(x^2+y^2)#

#• theta=tan^-1(y/x); -pi < theta <= pi#

#"here " (x,y)=(8,-15)#

#rArrr=sqrt(8^2+(-15)^2)=17#

#"now " 8-15i" is in the fourth quadrant so we must ensure"#

#"that "theta" is in the fourth quadrant"#

#theta=tan^-1(-15/8)=-1.08larrcolor(red)" in fourth quadrant"#

#rArr8-15ito(17,-1.08)#