Question

What is the Cartesian form of `(-9,(5pi )/4)`?

Answer 1

Cartesian form `(x,y)=(9/sqrt2,9/sqrt2)`

Explanation:

show below

polar form `(r,theta)=(-9,(5pi )/4)`

`x=r*costheta=-9*cos(5pi)/4=-9*-1/sqrt2=9/sqrt2`

`y=r*sintheta=-9*sin(5pi/4)=-9*-1/sqrt2=9/sqrt2`

Cartesian form `(x,y)=(9/sqrt2,9/sqrt2)`