ShmoopTube

Where Monty Python meets your 10th grade teacher.

Search Thousands of Shmoop Videos

GED Math 3.5 Graphs and Functions 309 Views


Share It!


Description:

GED Math: Graphs and Functions Drill 3, Problem 5. What is the negative root of the quadratic function?


Transcript

00:00

Thank you We sneak in and here's your smoke toos

00:05

your brought to you by negative roots there Not a

00:08

fan of the latest dye job What's The negative route

00:12

of the quadratic function F of x equals two x

00:15

squared plus nine x minus thirty five And here the

00:18

potential answer All right so this problem wants us to

00:23

find a negative route of a given function All right

00:26

well we should start by factoring the suckers Get it

00:29

its roots All right Well the first thing that shouldn't

00:32

jump out at us is the two coefficient in front

00:34

of our x squared term there Why Well because instead

00:38

of looking for two numbers that multiply to give us

00:40

negative thirty five like we usually would we instead need

00:44

two numbers that multiply to give us negative seventy court

00:48

two times as much to remember Those two numbers need

00:51

tto add up to nine match our middle term narrowing

00:55

our options here Good thing Well we've got ten and

00:59

negative seven or negative Ten and positive seventh but neither

01:04

of those was a nun Well what about negative fourteen

01:08

Five Who Closer Well there's no combination and negative Fourteen

01:11

and five It gives us nine But if we switch

01:14

the minus sign to the other guy while fourteen plus

01:17

negative five totally adds up to nine Now we can

01:20

factor way Start with f ax equals two x squared

01:22

plus fourteen x minus five x minus thirty five and

01:26

new little grouping to get f of x equals two

01:29

acts times the quantity x plus seven minus five times

01:33

the quantity x plus seven Then we factor we explosive

01:36

from both terms and we get f of x equals

01:39

the quantity to x minus five times the quantity x

01:41

plus seven go now it could solve for both routes

01:45

but we only want the negative one here The first

01:48

set of prints sees is going to lead us to

01:49

a positive number so we just zero in on the

01:52

second one and if x plus seven equals zero and

01:56

Acts would equal negative 7 answer choice eh We're pretty

02:00

proud of ourselves for attacking this problem so ruthlessly No

Up Next

GED Math 5.5 Graphs and Functions
882 Views

GED Math: Graphs and Functions Drill 5, Problem 5. What is the value of a?

Related Videos

GED Math 1.1 Measurement
326 Views

GED Math: Measurement Drill 1, Problem 1. The area, in square inches, of the shaded region where the two rectangles overlap is...what?

GED Math 1.1 Graphs and Functions
11927 Views

GED Math 1.1 Graphs and Functions. Which is the appropriate region of the coordinate plane?

GED Math 1.1 Expressions and Equations
878 Views

GED Math: Expression and Equations Drill 1, Problem 1. How much do the apples cost after tax?

Piecewise Functions
6147 Views

Don’t even think about starting up your combo lemonade/fro-yo stand without first making sure you understand piecewise functions. You’re just a...