SOLUTION: PLEASE HELP ME! HOMEWORK DUE SOON!! Find the equation of the circle passing through the points (-1,1) (1,3) and having the centre on the x-axis. Please help me!! The only part

Algebra ->  Circles -> SOLUTION: PLEASE HELP ME! HOMEWORK DUE SOON!! Find the equation of the circle passing through the points (-1,1) (1,3) and having the centre on the x-axis. Please help me!! The only part       Log On


   



Question 800476: PLEASE HELP ME! HOMEWORK DUE SOON!!
Find the equation of the circle passing through the points (-1,1) (1,3) and having the centre on the x-axis.
Please help me!! The only part of this question that i do not understand is the centre passing through the x-axis bit because if i knew the centre of this circle and two points then I will be able to do this question.
Please help me!! Thank You!

Answer by mananth(16946) About Me  (Show Source):
You can put this solution on YOUR website!
P(-1,1) Q(1,3)
center on x axis
so y co ordinate of center =0
let the center = O(x,0)
l(OP) =l(OQ)
(x+1)^2+(0-1)^2= (x-1)^2+(0-3)^2
x^2+2x+1+1 =x^2-2x+1+9
4x=8
x=2
The center = (2,0)
Now you can complete