# math

posted by .

a circle is tangent to the y-axis at y=3 and has one x-intercept at x=1
a) what's the other x-intercept
b) what's the equation

i have no clue how to solve this!

You know that the center of the circle is somewhere in the line y = 3, denote the x-coordinate by rx. Then the radius of the circle is |rx|. The distance from the center to the point x = 1 on the x-axis must be equal to the radius, which is |rx|. Therefore:

(rx-1)^2 + 9 = rx^2 --->

rx = 5.

Equation of the circle is thus:

(x - 5)^2 + (y - 3)^2 = 25

And you see that the other x intercept is at x = 9

## Similar Questions

1. ### calc

standard equations of circles that have centers on line 5x-2y=-21 and are tangent to both axis. Any ideas?
2. ### Slopes

Given y = 2x – 4, choose the statement that accurately describes this line. The slope is 2 and the y intercept is 4. The slope is 2 and the y intercept is -4. The slope is 4 and the y intercept is 2. The slope is -4 and they y intercept …
3. ### calc

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 …
4. ### math

A circle is tangent to the y-axis at y=3 and has one intercept at x=1. a) Determine the other x-intercept. b) Find the equation of the circle. Thanks for helping!
5. ### Circles (Conic Sections)

I have no idea how to do these problems: Find an equation of each circle. 1. Center (3,5); tangent to the x axis 2. Center (5,-3); tangent to the y axis 3. Tangent to the x axis, y axis, and the line y=5 (two answers) I just really …
6. ### Math

A circle is tangent to the y-axis at y=3 and has one x-intercept at x=1, find the other x-intercept and the equation of the circle. ...And if it's not any trouble, could you please explain how to do get there alongside showing me what …
7. ### Math

For the equation y = -6x, what is the slope and y intercept?
8. ### Algebra

What are the intercepts of the equation? Graph the equation. -3x + 4y = -12 A. x-intercept: (4, 0) y-intercept: (0, –3) B. x-intercept: (–3, 0) y-intercept: (0, 4) C. x-intercept: (4, 0) y-intercept: (0, –3) D. x-intercept: (–3,
9. ### math

1. two circles. x^2+y^2-16x-8y+35=0 and x^2+y^2=5 are given. a. write the equations in the standard form. b.prove that the circles touch each other. c.hence calculate the equation of their common tangent 2. find the equation of a. …
10. ### Geometry

How to put each circle in standard form? 1. Center of the line 5x-3y=12 and tangent to both axes.(first quadrant circle only). 2.passes through (-3,22) and tangent to the y axis at (0,19) 3.diameter ab with a (4,10) and b (8,14) 4.

More Similar Questions