# Thread: geometry help

1. ## geometry help

trying to find distance between 2 pts. using distance formula of
(1,4) (5,1)
I can get to the end of the problem, but the book says I'm wrong...

The answer I'm getting is the square root of 45, but the book says the answer is 3 times the square root of five.

Please tell me what I'm doing wrong.

2. You're not wrong at all. You just have to simplify $\displaystyle \sqrt{45}$

Look:

$\displaystyle \sqrt{45} = \sqrt{9 \cdot 5} = \sqrt{3^2 \cdot 5} = 3\sqrt{5}$

3. Thank you!

4. Originally Posted by dearjohn
trying to find distance between 2 pts. using distance formula of
(1,4) (5,1)
I can get to the end of the problem, but the book says I'm wrong...

The answer I'm getting is the square root of 45, but the book says the answer is 3 times the square root of five.

Please tell me what I'm doing wrong.
But both of you are not correct.

d = sqrt[(1 -5)^2 +(4 -1)^2]
d = sqrt[16 +9]
d = sqrt[25]
d = 5

5. Sorry..I gave the wrong coordinates for the wrong problem but Now I get it, so thanks to you both!!!!!!!!!!!!!!!