# Stuck while solving equation!

• Mar 5th 2010, 11:17 AM
crapmathematician
Stuck while solving equation!
I was solving an equation and got to a point where I have no clue what to do next! (Headbang) $\displaystyle 40.96=x^2-20x+y^2-22y+221$ As you can see I have to find x and y, looks simple, but damn I forgot how to solve it! (Angry) If anyone could help I would appreciate it a lot!
• Mar 5th 2010, 11:32 AM
bjhopper
Quote:

Originally Posted by crapmathematician
I was solving an equation and got to a point where I have no clue what to do next! (Headbang) $\displaystyle 40.96=x^2-20x+y^2-22y+221$ As you can see I have to find x and y, looks simple, but damn I forgot how to solve it! (Angry) If anyone could help I would appreciate it a lot!

you have two unknowns in one equation. You need another equation

bjh
• Mar 5th 2010, 11:33 AM
mathemagister
Quote:

Originally Posted by crapmathematician
I was solving an equation and got to a point where I have no clue what to do next! (Headbang) $\displaystyle 40.96=x^2-20x+y^2-22y+221$ As you can see I have to find x and y, looks simple, but damn I forgot how to solve it! (Angry) If anyone could help I would appreciate it a lot!

Could you post the whole question? There could be more information that would help you find the answer.
• Mar 5th 2010, 11:33 AM
crapmathematician
Quote:

Originally Posted by bjhopper
you have two unknowns in one equation. You need another equation

bjh

Could you be more precise?
• Mar 5th 2010, 11:41 AM
crapmathematician
Quote:

Originally Posted by mathemagister
Could you post the whole question? There could be more information that would help you find the answer.

The situation is: There are two points in a coordinate axis X1(10;11) and Xn(X;Y), the distance between these points is 6.4; Calculate the coordinates of Xn. I came up with that equation using the formula for distance between two points $\displaystyle d=\sqrt{(X2-X1)^2+(Y2-Y1)^2}$
• Mar 5th 2010, 12:03 PM
earboth
Quote:

Originally Posted by crapmathematician
The situation is: There are two points in a coordinate axis X1(10;11) and Xn(X;Y), the distance between these points is 6.4; Calculate the coordinates of Xn. I came up with that equation using the formula for distance between two points $\displaystyle d=\sqrt{(X2-X1)^2+(Y2-Y1)^2}$

You can't determine one specific point but you'll get a set of points which are placed on a circle around $\displaystyle X_1$ with radius 6.4.

The equation of the circle is:

$\displaystyle (x-10)^2+(y-11)^2=\frac{1024}{25}$
• Mar 5th 2010, 12:06 PM
masters
Quote:

Originally Posted by crapmathematician
The situation is: There are two points in a coordinate axis X1(10;11) and Xn(X;Y), the distance between these points is 6.4; Calculate the coordinates of Xn. I came up with that equation using the formula for distance between two points $\displaystyle d=\sqrt{(X2-X1)^2+(Y2-Y1)^2}$

Hi crapmathematician,

The locus of points (X, Y) which are at a given distance from a fixed point (10, 11) is a circle with center at (10, 11) and radius $\displaystyle 6.4$

The equation is $\displaystyle (x-10)^2+(y-11)^2=6.4^2$. There is an infinite number of values for (x, y) that will satisfy this equation.

Never mind! Earboth, you da man!