Posted by **Nikki** on Saturday, November 14, 2009 at 4:07pm.

Determine an equation of the circle that is tangent to both axes, has its center in the fourth quadrant and passes through the point (8, -9).

Help please?

Thanks much!

- Math -
**bobpursley**, Saturday, November 14, 2009 at 4:22pm
well, you know if it is tangent to both axis, the center is at r,-r

It passes through 8,-9 so the distance from that point to the center is also r.

r^2=(8-r)^2 + (-9+r)^2

= 64-16r+r^2+81-18r+r^2

r^2-34r-145=0

(r-29)(r-5)=0

r=29, or r=5

check both answers.

then put it in standard form.

## Answer this Question

## Related Questions

- mathematics - The circle x2-2x+y2-4y-4=0 lies on the cartesian plane,question 2....
- mathematics - The circle x2-2x+y2-4y-4=0 lies on the cartesian plane,question 2....
- mathematics - The circle x2-2x+y2-4y-4=0 lies on the cartesian plane,question 2....
- Analytic Geometry - Give the equation of the circle tangent to both axes of ...
- math - can u help this the qustion is : A circle passes through the points (1,4...
- math - determine the equation of a circle that has its center a (0,0) and passes...
- geometry - find the equation of the circle having center on 3x+y=6 and tangent ...
- steev - can u help this the qustion is : A circle passes through the points (1,4...
- mathematics - The circle x2-2x+y2-4y-4=0 lies on the cartesian plane,question 2....
- maths - 1) Circle centre (7,-2) passes through (-2,10). Calculate radius and ...