SOLUTION: Ok, so i'm doing a few problems for my summer homework and one of the many sheets is about the distance formula. The two points are (-6.8, 0.7) and (-2.1, -6.2). I did the math and

Algebra ->  Coordinate-system -> SOLUTION: Ok, so i'm doing a few problems for my summer homework and one of the many sheets is about the distance formula. The two points are (-6.8, 0.7) and (-2.1, -6.2). I did the math and      Log On


   

Question 332622: Ok, so i'm doing a few problems for my summer homework and one of the many sheets is about the distance formula. The two points are (-6.8, 0.7) and (-2.1, -6.2). I did the math and ended up with Square Root 22.09 + Square Root 7.84 which equals Square Root 29.93 . But, on the schools website they have answer-sheets and they put the answer as 8.34865. Can someone explain please?
Found 2 solutions by Edwin McCravy, solver91311:
Answer by Edwin McCravy(20060) About Me  (Show Source):
You can put this solution on YOUR website!

You used the wrong formula.

d=sqrt%28%28-2.1-%28-6.8%29%29%5E2%2B%28-6.2-%280.7%29%29%5E2%29

d=sqrt%28%28-2.1%2B6.8%29%5E2%2B%28-6.9%29%5E2%29

d=sqrt%28%284.7%29%5E2%2B%28-6.9%29%5E2%29

d=sqrt%2822.09%2B47.61%29

d=sqrt%2869.7%29

d = 8.348652586

Edwin

Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!


Well, you did the math, but at some point you weren't doing the right math. First let's clear up what looks like a misconception on your part.

Not sure if this is exactly what you meant, but this is what you said:



Not true. In general,



Although, I don't think this is what you really meant because you should never have gotten to the point where you were adding two radicals when you were simply trying to find the distance between two points.

The next thing that is hokey is that you have 7.84, which is 2.8 squared which looks like you subtracted the y coordinate of the first point from the x coordinate of the second point -- oops!

What you should have done:









You good to go from here?

John

My calculator said it, I believe it, that settles it