# AS Geometry query

• Apr 4th 2012, 10:25 PM
FH88
AS Geometry query
I'm currently stuck on the following question:

The distance between the two points A(6, 2p) and B(p, -3) is 5√5.
Find the possible values of p.

Is this a simple trial and error solution?
• Apr 4th 2012, 10:40 PM
princeps
Re: AS Geometry query
Quote:

Originally Posted by FH88
I'm currently stuck on the following question:

The distance between the two points A(6, 2p) and B(p, -3) is 5√5.
Find the possible values of p.

Is this a simple trial and error solution?

Hint :

$\displaystyle \sqrt{(x_B-x_A)^2+(y_B-y_A)^2}=5 \cdot \sqrt 5$
• Apr 4th 2012, 10:52 PM
biffboy
Re: AS Geometry query
Difference of x coordinates=6-p
Difference of y coordinates=2p-(-3)=2p+3
Squaring both sides of distance formula we have (6-p)^2+(2p+3)^2=(5root5)^2=125
Remove brackets and solve equation (should get p=+2 or -2)
• Apr 5th 2012, 12:30 PM
bjhopper
Re: AS Geometry query
11^2 + 2^2 = 125.Find by trial (-5.-3) ( 6,-5) p=-5 and (6,8) (8,-3) p=8