#Quadratic Functions

177 messages · Page 1 of 1 (latest)

fiery acorn
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Please help me solve this equation with the topic/concepts needed along with listing the formulas later to solving it helping me.

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thin needle
fiery acorn
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its cause its from my phone

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is png fine

keen axle
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screen shot it then

thin needle
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as long as you post it... and it can be seen w/o having to download it

fiery acorn
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Should work now

thin needle
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ok, what have you tried?

fiery acorn
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Nothing because im so lost. I wrote down the "concepts" that I thought I needed

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But idk if i even need them now

thin needle
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ok... well what are the roots of f in terms of p and/or a?

fiery acorn
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Does that mean finding the zeroes

thin needle
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roots and zeros are synonymous, yes

fiery acorn
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I have not tried that. Would I just set X to 0? I don't remember the formula at all which sucks

thin needle
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what's the definition of zeroes?

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there's no formula, it's just definition and logic

fiery acorn
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Isn't it related to the y/x intercept

thin needle
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the zeroes are the x value st f(x)=0.

keen axle
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x intercept

thin needle
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as your notes would say

fiery acorn
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Ok

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So would I do

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f(x) = a(0-p)(0-3)?

thin needle
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clearly not

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that's plugging in x=0

thin needle
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what does "f(x)=0" look like, given you know explicitly what f(x) is

fiery acorn
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its setting the equation to be equal to zero isn't it not

keen axle
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yes

thin needle
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so do so

thin needle
keen axle
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you are simply solving for the roots or solutions

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did i ask?

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if an explanation does not make sense to the student. You must make it simpler.

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Not everyone understands math the way you do.

thin needle
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Cool, and the courtesy of the server is if someone is already helping, you let them help blobshrug

keen axle
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sorry about that @fiery acorn

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It is what i was clearly doing

thin needle
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if they dont understand an explanation, they can simply say that themselves lol

fiery acorn
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Lmao trust me all good, ill take the help anyways

keen axle
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he asked a question you made it complicated, i answered his questions.

fiery acorn
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Ok so

thin needle
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sure, whatever you say blobshrug

fiery acorn
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would it be

keen axle
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okay bosco

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ask your question

thin needle
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their question was asked ages ago

keen axle
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the smart guy should be able to help you

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he has other questions to ask.

fiery acorn
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f(x) = a(2.5-p)(2.5-3) = 0

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Nah its just i haven't done this in so long

keen axle
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first lets find the value of p

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as it is more easier

fiery acorn
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Ok

keen axle
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you are given the axis of symmetry

fiery acorn
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Correct which is X

keen axle
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yes

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the axis of symmetry’s x coordinate is the vertex to our quadratic

fiery acorn
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Yeah

keen axle
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you understand that explanation right

fiery acorn
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Vertex is the middle point isnt it not

keen axle
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yes

fiery acorn
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Yeah

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Ok so I would have to plug in 2.5?

keen axle
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not directly

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but we can use that information to find p

fiery acorn
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Ok

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We also have the y-intercept too

keen axle
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when we have our factored form quadratic

fiery acorn
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Yeah

keen axle
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we can find the vertex by adding the roots, p and q and then dividing it by 2

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to give us the x coordinate

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of the vertex(AOS)

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so what do you think we should do

fiery acorn
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I mean you said the x coordinate of the AOS but AOS x = 2.5

keen axle
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yes thats the coordinate

fiery acorn
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Ok but we don't have p and q for the vertex so we'll need to find it

keen axle
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but we will then have to set it equal to 2.5 and solve for p

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we have q

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which is 3

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(x-3)

fiery acorn
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Ok

keen axle
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so we have this formula to find the midpoint of p and q

fiery acorn
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p + q/2?

keen axle
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yeah

fiery acorn
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Oh that

keen axle
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we have x and q

fiery acorn
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Whats that formula called

keen axle
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so now we are solving for p

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midpoint formula

fiery acorn
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Midpoint as in vertex?

keen axle
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midpoint generally

fiery acorn
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Is there another term

keen axle
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its just the the coordinate in between the two values

fiery acorn
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cause I remember that formula

thin needle
fiery acorn
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Ok i wrote the formula down

keen axle
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okay

fiery acorn
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X would be 2.5

keen axle
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now just plug in x and q

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then solve for p

fiery acorn
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is it p = 2.5 - 3/2 to solve?

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Yeah right?

keen axle
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no

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you would need to multiply the entire equation by two to get rid of the fraction

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and then solve for p, then

fiery acorn
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Yeah I had 2.5 x 2

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which is 5

keen axle
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yeah

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and then you get

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$p+3=5$

shell hedgeBOT
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ビジヨン

keen axle
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and you just solve that

fiery acorn
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Ok so P is 2. But I would have to rearrange that to show. Being 5 - 3 = p which is 2

keen axle
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yes that’s basically correct

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now you have p and q so you have a(x-2)(x-3)

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(0,-6) is the y intercept

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you have f(x)=a(x-2)(x-3) as your current function right?

fiery acorn
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Yeah with the p plugged in

keen axle
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now how would you find a

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using the y intercept as information

fiery acorn
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Don't remember. I had an idea to do f(0) = -6(0-2)0-3) but idk if that would work

keen axle
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a isnt -6

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but we are given (0,-6)

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this tells us that when x=0 y is?

fiery acorn
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-6

keen axle
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yup

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so we have f(0)=?

fiery acorn
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-6

keen axle
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yup

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now plug in 0 into f(x) and once you solve the right hand side

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substitute f(0) with -6

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tell me what you get for a

fiery acorn
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Hm

keen axle
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what do you have?

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$f(0)=a(-2)(-3)$

shell hedgeBOT
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ビジヨン

fiery acorn
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a should be 6

keen axle
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you get

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$f(0)=6a$

shell hedgeBOT
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ビジヨン

keen axle
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right?

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but remember

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$f(0)=-6$

shell hedgeBOT
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ビジヨン

fiery acorn
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It should be 1 right

keen axle
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should it?

fiery acorn
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Wait it was just at 6a

keen axle
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yeah

fiery acorn
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how did you isolate it

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I thought you did

keen axle
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but we are told the y intercept is (0,-6)

fiery acorn
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6/6 = a

keen axle
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so when x=0 y is -6

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and we know f(x) and y are the same thing

fiery acorn
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Ok

keen axle
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so replacing f(0) in whichever we end up getting

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$6a=-6$

shell hedgeBOT
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ビジヨン

keen axle
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because we have

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$f(0)=6a$ and $f(0)=-6$

shell hedgeBOT
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ビジヨン

fiery acorn
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a is -1

keen axle
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yes

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you understood right?

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the process of how to find p and q?

fiery acorn
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Yeah

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the only thing is

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I have to list all the formulas and rules to solve the problem as well

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So like I have x = p+q/2

keen axle
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for the vertex/AOS

fiery acorn
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Yeah but isn't that not the AOS version

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Actually I got it