March 30, 2013

## How to find the equation of a circle tangent to another circle?

So basically I am given the center of the unknown circle (x1,y1), that is tangent to the known circle (ax^2+by^2+cx+dy+e=0 where a,b,c,d,e are all real integers). What are the steps to finding the unknown circle?

The steps are:
1. Complete the square(s) in the known circle’s equation to find the known circle’s radius and centre.
2. Find the distance between the centres of each circle by using the distance formula.
3. Subtract the known circle’s radius from this distance to obtain the unknown circle’s radius.
4. Use the unknown circle’s radius and centre to construct its equation.

Step 3 works because both circles are tangent to each other, so the shortest distance between their centres is the sum of their radii.

## How can i use an equation to preform regression analysis?

I have come up with an equation without any data points.
Y = 105 – 75 X1 + 100 X2 + 10 X3 + 15 X1 X3
Is there a way to preform regression analysis using only this equation?
I know there is a way to do this using data points and excel but i do not have the points.

As far as I’m aware, the purpose of doing a regression analysis is to determine the constant coefficients of an equation by minimizing the error between each model predicted value and the known value. To do that, you need to have the original data.

## does it cost much to replace the screen on a xperia x1?

kay so i have a sony Ericsson xperia x1 and the screen broke after a bike accident dose it cost much to get a new screen?
and this is in australia =)

It would probably cost around 60\$, but my friend’s dad fixed it so I’m not really sure.

## what kind of adhesive can i use?

i want to bond 12″x12″x1” squares of cement to a cament wall.it is outside and subject to direct sun in the summer.

A good thinset with epoxy grout.

## Find the Slope of the line through the following pair of points using the slope Formula?

The two pairs are (-7,-12) and (-2,6)

Slope line formula: (y-y1)=m(x-x1)

Thanks for the help guys!
If you could Also explain how to work the Problem, I would really appreciate it.

(-7, -12) and ( -2, 6)

(y – y1) = m(x – x1)

[(-12) - (6)] = m[( -7) - (-2)]

-18 = m(-5)
/-5 /-5

+18 / 5 = m