Posted by **sammy** on Saturday, September 1, 2007 at 5:07pm.

a circle is tangent to the y-axis at y=3 and has one x-intercept at x=1

1. determine the other x-intercept

2. find an equation for the circle

so i know two points on the circle are (0,3) and (1,0) and the equation for a circle is (x-a)^2 + (y-b)^2 = r^2 but i don't know how to solve the two questions

- calc -
**Count Iblis**, Saturday, September 1, 2007 at 5:53pm
The circle is tangent to the y-axis at y = 3. From this it follows that the center of the circle must be located somewhere on the line y = 3. Therefore b = 3.

The point (0,3) is on the circle, so:

a^2 = r^2

The point (1,0) is on the circle:

(1-a)^2 + 9 = r^2

Suntracting these two equations gives:

a^2 - (1-a)^2 = 0 ---->

(2a - 1) =0---->

a = 1/2

And for this you can easily find r.

## Answer This Question

## Related Questions

- math - A circle is tangent to the y-axis at y=3 and has one intercept at x=1. a...
- math - a circle is tangent to the y-axis at y=3 and has one x-intercept at x=1 a...
- Math - A circle is tangent to the y-axis at y=3 and has one x-intercept at x=1, ...
- 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....
- 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 ...
- math - 1. two circles. x^2+y^2-16x-8y+35=0 and x^2+y^2=5 are given. a. write the...
- Pre-Calc - Describe the conditions necessary for the two circles, where circle a...

More Related Questions