How do you convert the rectangular point #(-3,3sqrt3)# into polar form?

1 Answer
Sep 10, 2016

#(6,-pi/3)#

Explanation:

To convert from #color(blue)"rectangular to polar form"#

That is #(x,y)to(r,theta)#

#color(orange)"Reminder " color(red)(bar(ul(|color(white)(a/a)color(black)(r=sqrt(x^2+y^2))color(white)(a/a)|)))#

and #color(red)(bar(ul(|color(white)(a/a)color(black)(theta=tan^-1(y/x))color(white)(a/a)|)))#

here x = - 3 and #y=3sqrt3#

#rArrr=sqrt((-3)^2+(3sqrt3)^2)=sqrt(9+27)=sqrt36=6#

Now,# (-3,3sqrt3)# is in the 4th quadrant so we must ensure that #theta# is in the 4th quadrant.

#theta=tan^-1((3sqrt3)/(-3))=tan^-1(-sqrt3)#

#=-pi/3larr" in 4th quadrant"#

Thus #(-3,3sqrt3)to(6,-pi/3)to(6,-60^@)#