#Hey Can I have help with this question?

143 messages · Page 1 of 1 (latest)

north wyvern
pulsar galeBOT
clever quarry
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you can get two points on the graph from the information the first bullet point provides

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do you know what those are?

north wyvern
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Y int -2 and X int (7x-2)?

clever quarry
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not exactly

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if i told you a graph had a y intercept of 5

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basically this line

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what would the point at the y intercept be, in terms of (x,y) ?

north wyvern
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0,5

clever quarry
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right

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now if the x intercept is 2/7, what would that point be as (x,y) ?

north wyvern
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Pretty much a straight line

clever quarry
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well the x intercept means the graph intersects the x-axis at some point

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it intersects at the x value of 2/7

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but what is the y value?

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think about what the y value of the x axis is

north wyvern
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0

clever quarry
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exactly

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meaning that the graph will intersect the point (2/7 , 0)

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so now you have two intersection points of (0,5) and (2/7,0)

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since this line is linear, you should be able to find the slope of the line

north wyvern
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I just need to find absolute value function do I need slope?

clever quarry
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you'll have to have some equation y = mx + b, where m is the slope

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so yes

north wyvern
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So for finding slope without a diagram how do i do that

clever quarry
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im guessing you normally find slope doing "rise over run" right?

north wyvern
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Yes

clever quarry
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rise over run is really a visual way to describe the change in the height over a change in distance

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meaning the change in y values divided by the change in x values

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essentially, if you have two points on the graph, say (x1, y1) and (x2, y2), the slope of the line is given:

m = (y2 - y1) / (x2 - x1)

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the "rise" (change in height) over the "run" (change in horizontal distance)

north wyvern
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2-0 and 0-2/7

clever quarry
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(0,5) and (2/7,0) are your points

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so call (0 , 5) to be (x1,y1)

north wyvern
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Isnt it 0,2

clever quarry
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oh it is lmao

north wyvern
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Y int is 2 on the question

clever quarry
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sorry

north wyvern
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All g

clever quarry
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what does this simplify to

north wyvern
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2 over 2/7

clever quarry
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yes

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which equals what?

north wyvern
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7

clever quarry
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good, so that is the slope of the line

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you can get the equation of the line now by using point slope form

north wyvern
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so equation is at y=7x + 2

clever quarry
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great

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so there's one more thing, that being the absolute value

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do you see what to do?

north wyvern
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Putting the absolute value sign around the equation?

clever quarry
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it shold be -7x

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not postivie

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because 0 - 2/7 is negative

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and you had 2 / (-2/7)

north wyvern
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Ok I understand that

clever quarry
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okay, the equation is still right

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so now you just need the absolute around -7x + 2

north wyvern
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So the absolute value is what x cannot equal

clever quarry
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the abosulte value just makes a negative number positive

north wyvern
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So is this correct

clever quarry
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perfect

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yep

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here is the graph to verify

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.286 = 2/7

north wyvern
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I totally understand if you dont want to but I have a couple more questions if you wanna help

clever quarry
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i have time for maybe 1 more

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sorry

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but i can do it

north wyvern
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Totally understand you are taking time to help without being paid no need to apologize

clever quarry
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appreciate it

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send another we'll do it

north wyvern
clever quarry
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okay, so what helps is seeing that there exists x intercepts

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one at -3, and one at 1

north wyvern
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Ok and then Maxiumum at 4

clever quarry
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consider if i gave you the quadratic equation
x^2 + 4x - 5 - 0
to solve for x, you would do
(x+5)(x-1) = 0
and therefore,
x = -5 and x = 1

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is this familiar?

north wyvern
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Been a while since ive done quadratic equations

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But I get the solving

clever quarry
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okay good

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so notice the (x+5)(x-1) = 0 part

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this correlates to solutions for when the graph intersects the x axis

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that being at x = -5, x = 1

north wyvern
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Yes

clever quarry
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so that means that if we have solutions at x = -3 and x = 1

north wyvern
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Im stuck at this part

clever quarry
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understandable it's tricky

clever quarry
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so if i have x = -3

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that had to of come from (x+3) = 0

north wyvern
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X cannot equal 3

clever quarry
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x is negative 3

north wyvern
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Ok I get x=-3 and +1

clever quarry
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right

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and x = -3 came from (x + 3) = 0

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and the +1 from (x - 1) = 0

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so therefore, this parabola must have the factors of (x + 3) and (x - 1)

north wyvern
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Ok

clever quarry
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note if i plug these factors into a graph, this is the result

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the last step is to make sure all y values are greater than 0

north wyvern
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So just changing them to anything?

clever quarry
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well all we need to make sure is that
y = (x+3)(x-1)
is always greater than or equal to 0

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to do that think about the last problem

north wyvern
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Do we need slope? n

clever quarry
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not slope, but absolute brackets

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remember that if i have-5, and i do
| -5 |
it equals positive 5

north wyvern
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So y=(x+3)(x-1) in ab brackets creates the graph

clever quarry
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yes

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this is your answer

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and the graph

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note that this is the equation without abs brackets

north wyvern
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I see makes sense

clever quarry
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note how the part that is below the x - axis in the green is reflected

north wyvern
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It says I need 2 equations will flipping the signs give the same result

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No It wont

clever quarry
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it wont, good catch

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well we have (x+3)(x-1)

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so i think if we just foil it is acceptable

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or distribute is the better wording

north wyvern
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X^2 +2X -3

clever quarry
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good

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that in abs brackets is equal to |(x+3)(x-1)|

north wyvern
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So Y equals that will be my second equation?

clever quarry
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yep

north wyvern
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With brackets correct?

clever quarry
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yes

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because you still want y >= 0

north wyvern
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Thank you very much

clever quarry
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of course, that's all i got time for

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good luck!

north wyvern
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Wait im not too sure

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This gives me this

clever quarry
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zoom in and it should look better

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note where it hits on the x and y axis is accurate

north wyvern
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If yoy have the chance can you confirm if the answrs 1/(x-(-2/3)) and 1/((-2/3)-x) are right for this problem

quaint mango
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