# Distance formula

• Jan 30th 2013, 01:13 PM
goldbug78
Distance formula
I have to find the distance for the the points -1,1 at 135 degrees. (Find the distance d from the origin to that point) Using the distance formula, I am getting a 0. Is this correct?
• Jan 30th 2013, 01:30 PM
ebaines
Re: Distance formula
It should be obvious that the distance between the point (1,1) and (0,0) is not 0. The formula for distance betwen points A and B is:

$d = \sqrt{(x_A - x_B)^2 + (y_A - y_B)^2}$

Here point A is $(x_A,y_A) = (1,1)$ and point B is $(x_B,y_B)=(0,0)$.
• Jan 30th 2013, 01:54 PM
goldbug78
Re: Distance formula
so 2 squared then?
• Jan 30th 2013, 02:02 PM
ebaines
Re: Distance formula
Not 2 squared, but square root of 2.
• Jan 30th 2013, 02:03 PM
Plato
Re: Distance formula
Quote:

Originally Posted by goldbug78
so 2 squared then?

Please tell us what "I have to find the distance for the the points -1,1 at 135 degrees." means.

What does $135^o$ have to do with any of this?
• Jan 30th 2013, 02:17 PM
ebaines
Re: Distance formula
Quote:

Originally Posted by Plato
What does $135^o$ have to do with any of this?

I think the OP is just saying that a line from the origin to the point (-1,1) is at an angle of 135 degrees from the +x axis. I considered it extraneous information.