How do you convert polar equations to Cartesian equation given theta = pi/3θ=π3?

1 Answer
Nov 15, 2016

Please see the explanation

Explanation:

pi/3π3 is in the first quadrant, therefore, we substitute tan^-1(y/x)tan1(yx) for thetaθ and add the restriction x > 0 and y > 0x>0andy>0:

tan^-1(y/x) = pi/3; x > 0 and y > 0tan1(yx)=π3;x>0andy>0

Use the tangent function on both sides:

tan(tan^-1(y/x)) = tan(pi/3); x > 0 and y > 0tan(tan1(yx))=tan(π3);x>0andy>0

The tangent function "undoes" its inverse and tan(pi/3)tan(π3) has a well known value:

y/x = sqrt(3); x > 0 and y > 0yx=3;x>0andy>0

Multiply both sides by x and drop the restriction on y, because it is now dependent on x:

y = sqrt(3)x; x > 0y=3x;x>0