# TSI Math: Writing the Equation for a Line's Bisector

A line has endpoints A (0, 6) and B (-2,-10). Which of the following is the correct equation of the perpendicular bisector of this line?

Geometry and Measurement | Plane Geometry |

Mathematics and Statistics Assessment | Plane Geometry |

Product Type | TSI |

TSI | Mathematics and Statistics Assessment TSI Math TSI Mathematics |

TSI Math | Geometry and Measurement |

TSI Mathematics | Geometry and Measurement |

Test Prep | TSI |

### Transcript

sure it's got plenty of battery left because we're going

on a hunt Were hunting for a line which if

you consider getting a poor grade a matter of life

and death can be as dangerous as hunting lion All

right find this particular line were given a few clues

We're told the line is the perpendicular by sector of

a line within point So six and negative too negative

ten which is really all the information we need Because

we'll be able to find its slope here pretty easily

The line is the perpendicular by sector of line segment

a bee So its slope will be the negative reciprocal

of the slope of a bee Let's find that slope

first and we've got the whole why to money is

why one over x human sex One thing that's what

it looks like six minus eight Ten over zero money

thing to its sixteen over two or eight Voila The

negative reciprocal of aid is negative One eighth All right

so we can get rid of a and we can

get rid of sea right off the bat And actually

we can get rid of dia's Wells is not negative

So just by process of elimination we're kind of there

already But let's keep going Now that we have our

slope i really have to make sure that the line

passes through the mid point of a b to find

the midpoint of baby We'll use another one of our

trusted formulas The midpoint formula Okay so here it is

Ah this ugly thing here and we get what is

that Quantities europe listening to over to you And then

six plus minus ten answering for over two And all

that boils down Teo what is that Negative one Negative

too We need a line that passes through the point

negative one negative too and has a slope of negative

one eighth which we can easily find by plugging in

the x and y value right there Plus the slope

into the y equals mx plus b thing So that

gives us negative too is a negative one Eighth time

to think of one plus b or negative too is

when a plus b bringing the one eighth over there

on the far side And we get negative Seventeen Eight

is be so Our final equation is y equals negative

one eighth axe minus seventeen over eight And yeah that's 00:02:16.32 --> [endTime] Just be we're done for shmoop