How do you convert ( 1 , - sqrt3 )(1,3)into polar coordinates?

1 Answer
Jan 9, 2016

If (a,b)(a,b) is a are the coordinates of a point in Cartesian Plane, uu is its magnitude and alphaα is its angle then (a,b)(a,b) in Polar Form is written as (u,alpha)(u,α).
Magnitude of a cartesian coordinates (a,b)(a,b) is given bysqrt(a^2+b^2)a2+b2 and its angle is given by tan^-1(b/a)tan1(ba)

Let rr be the magnitude of (1,-sqrt3)(1,3) and thetaθ be its angle.
Magnitude of (1,-sqrt3)=sqrt((1)^2+(-sqrt3)^2)=sqrt(1+3)=sqrt4=2=r(1,3)=(1)2+(3)2=1+3=4=2=r
Angle of (1,-sqrt3)=Tan^-1(-sqrt3/1)=Tan^-1(-sqrt3)=-pi/3(1,3)=tan1(31)=tan1(3)=π3

implies Angle of (1,-sqrt3)=-pi/3(1,3)=π3

But since the point is in fourth quadrant so we have to add 2pi2π which will give us the angle.

implies Angle of (1,-sqrt3)=-pi/3+2pi=(-pi+6pi)/3=(5pi)/3(1,3)=π3+2π=π+6π3=5π3

implies Angle of (1,-sqrt3)=(5pi)/3=theta(1,3)=5π3=θ

implies (1,-sqrt3)=(r,theta)=(2,(5pi)/3)(1,3)=(r,θ)=(2,5π3)
implies (1,-sqrt3)=(2,(5pi)/3)(1,3)=(2,5π3)
Note that the angle is given in radian measure.

Note that the answer (1,-sqrt3)=(2,-pi/3)(1,3)=(2,π3) is also correct.