SOLUTION: I have got a question could someone explain to me how to convert this into polar coordinates; x^2 + y^2 = 4x

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Question 232501: I have got a question could someone explain to me how to convert this into polar coordinates;
x^2 + y^2 = 4x
Answer by rapaljer(4671) About Me  (Show Source):
You can put this solution on YOUR website!
x^2+y^2=r^2

x=r*cos(theta)
y=r*sin(theta)

Substitute these into x^2 + y^2 = 4x
r^2=r*cos(theta)

Set equal to zero,
r^2 -r*cos(theta)=0

Factor out the r:
r(r-cos(theta)) =0 There are TWO solutions.

FIRST SOLUTION:
r=0 which is just a point (0,0)

SECOND SOLUTION:
r-cos(theta) =0
r=cos(theta)

Since the second solution includes the point (0,0), this is automatically included in second solution. The final answer is r=cos(theta).

Dr. Robert J. Rapalje
Seminole State College of Florida