Thursday

February 26, 2015

February 26, 2015

Posted by **Christina** on Friday, September 16, 2011 at 11:44am.

(0,4),(7,-6),(-5,11).

I know the distance formula, but I don't see how that will help me find out if they lie on the same line.

- Math -
**Reiny**, Friday, September 16, 2011 at 12:51pmdistance between (0,4) and (7,-6) = √(49+100) = √149

distance between (7,-6) and (-5,11) = √(144+289) = √433

distance between (0,4) and (-5,11) = √(25+49) = √74

if they are collinear, then

√74 + √149 = √433

IS it ??

√74 + √149 = 20.80888088

√433 = 20.80865205

difference is .000228

had you simply graphed it, you would not have noticed the difference, but there is a difference, so the points are NOT collinear.

check: slope of 1st segment = -10/7

slope of another segment = 7/-5

since -10/7 ≠ -7/5 , they are not collinear.

(notice the slopes are close)

-1.42857 vs -1.4 , angles are 55.0° vs 54.5°

**Answer this Question**

**Related Questions**

Math - Rewrite the following definition as a biconditional: Points that lie on ...

????Math Question????8th grade adv.math - Algebra! How is the distance formula ...

Algebra 2 - 1. Give 3 points that lie on the line 4x-y=6. 2. Give 3 points that ...

Algebra 2 - 1. Give 3 points that lie on the line 4x-y=6. 2. Give 3 points that ...

Algebra 2 - 1. Give 3 points that lie on the line 4x-y=6. 2. Give 3 points that ...

CALCULUS 3 - Use the triple scalar product to determine whether the given points...

Geometry, Help - 1. Reasoning How does the Distance Formula ensure that the ...

English - I need a opening line which will grab my reader's attention right away...

Geometry - 4.Determine which point does not lie on the graph of the line y=x-3 a...

Linear Algebra - In 3-space, a plane abc is spanned by three points a, b, c. The...