ShmoopTube

00:01

Okay Math geeks we have another one for you A

00:04

diagram of a line segment Right there It's Ah that

00:07

thing All right What's the length of the line segment

00:15

What length of a line segment is equal to the

00:17

distance between the end points Does that sounds vaguely uplifting

00:21

Sort of Anything that belongs on a line of inspirational

00:24

math posters The end points in this case are negative

00:27

Seven negative too right there And then five four right

00:30

there Although well that phrasing doesn't quite have that eci

00:34

poster idiom feel to it So we just plug these

00:36

coordinates into the distance formula This thing here is the

00:40

square root of x to minus x one squared plus

00:43

y two months like one squared So then we just

00:45

plug in the Numbers We got 5 minus and seven

00:48

squared plus four months and two squared And then we

00:50

simplified and we get twelve squared plus six squared under

00:54

the little thing You there and then we got one

00:56

forty four plus thirty six One is a total one

00:58

eighty square root of one eighty Well we gotta find

01:01

square one eighty now who just factor out a few

01:03

perfect squares And that's what is that Nine and twenty

01:06

And then we take a five and a four out

01:08

of twenty there forgets his nine Forty five Well what

01:11

do you know Nine in for our perfect squares We

01:13

got three squared times Two squared times five All right

01:16

so now we take purpose wears out of the radical

01:19

and it looks like that So we got well what

01:21

is that Three times two times square with a five

01:25

or well just six times square with five The length

01:28

of line segment is that six times square to five

01:31

And if you found that length of line segment was

01:33

to liken eh They trick you You may have incorrectly

01:36

dealt with the double negatives in the distance formula by

01:39

using square root of five minus seven square plus four

01:44

minus two spurred instead of the more correct five minus

01:47

a negative seven and four months And negative too It's

01:50

okay to where the journey is equal to the destination

01:53

or something that didn't aerosmith say that

Full Transcript