Question

How do you find the equation for a circle that passes through the origin and has intercepts equal to 1 and 2 on the x- and y- axes?

Answer 1

`x^2+y^2-x-2y=0`.

Explanation:

Let the equation be `x^2+y^2+2gx+2fy+c=0`.
This passes through (o, 0), (1, 0) and (0, 2).
So, c = 0, g = `-1/2` and `f=-1`
Answer: `x^2+y^2-x-2y=0`.