Posted by **Josh** on Wednesday, January 20, 2010 at 7:01pm.

Find all the points having an x coordinate of 2 whose distance from the point (-1,-5) is 5.

so far i have

5=sqrt((-1-2)^2+(-2-y)^2)

5=(-3)^2

how do i simplify the rest of the equation so i can find x. do i foil it out? thanks.

- Trig/Math -
**MathMate**, Wednesday, January 20, 2010 at 8:09pm
Geometrically, you are looking for the intersection of a vertical line (x=2) with a circle centred at (-1,-5) with a radius of 5.

Line L1: x=2

Circle C1: (x-(-1))²+(y-(-5))²=5²

(x+1)²+(y+5)²=25

Substitute x=2 in C1:

(2+1)²+(y+5)²=25

(y+5)²=25-3²=16=4²

(y+5) = ±4

So there are two solutions, y=-9 or y=-1

- Trig/Math -
**Josh**, Wednesday, January 20, 2010 at 10:27pm
thank you!!

- Trig/Math :) -
**MathMate**, Thursday, January 21, 2010 at 12:11am
You're welcome.

Do give a check on the distance between the centre and the intersection points to complete the question.

## Answer this Question

## Related Questions

- math - Find all the points having an x-coordinate of 9 whose distance from the ...
- Advanced Math - find all points having an x-coordinate of 2 whose distance of ...
- Algebra - find all points having an x-coordinate of 4 whose distance from the ...
- Math - Find all points having x-coordinate 9 and distance 10 from the point (3,-...
- ????Math Question????8th grade adv.math - Algebra! How is the distance formula ...
- Calculus - the curve: (x)(y^2)-(x^3)(y)=6 (dy/dx)=(3(x^2)y-(y^2))/(2xy-(x^3)) a...
- math-Inverse functions - f(x)=-4x-2 & g(x)=5x-6. Find (f*g) and state domain. f(...
- math - Alright, let's say you want to get from one point to another, in a 3D box...
- algebra,math,help - Use Property 2 to simplify each of the following radical ...
- math - how would you simplify this equation: y = (x+3)/[(4-sqrt(16+h))] please ...

More Related Questions