#help me simplify this

79 messages · Page 1 of 1 (latest)

mystic brook
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idk where to start

twilit lake
mystic brook
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i tried

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idk how to start

twilit lake
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There are two ways

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To solve this, either simply using the factoring method which is a very straightforward method or you can use the quadratic formula to find the zeros

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Let's go with the factoring method because it's less tedious

mystic brook
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could u show me this method

twilit lake
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I'll show the quadratic formula too, so you know the difference

mystic brook
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ok

twilit lake
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let me just test the latex

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$asad$

meager scaffoldBOT
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せんく(It's Quantum)

twilit lake
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great it works

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factoring method:\
$x^2+2x-3$, find two numbers when multiplied with each other gives us -3 and and when added gives us 2. The best candidat for that is, 3 and -1. \
so our zero's are at point, -3 and 1. Which imples that we can rewrite our function to: (x+3)(x-1)

meager scaffoldBOT
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せんく(It's Quantum)

mystic brook
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so u did 2 -3

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then added 3

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?

twilit lake
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quadratic formula method: \
This method goes to find the zero's of the functions i.e x values for which the function gives us zero. for that we apply the quadratic formula:\
for functions with form ax^2+bx+c \
gives the roots of the function \
substituting the coefficients we get similar solutions as one above.

twilit lake
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$\frac{-b \pm \sqrt{b^2-4ac}}{2a}$

meager scaffoldBOT
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せんく(It's Quantum)

twilit lake
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quadratic formula method: \
This method goes to find the zero's of the functions i.e x values for which the function gives us zero. for that we apply the quadratic formula:\
for functions with form ax^2+bx+c \

mystic brook
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yea i know that one

twilit lake
mystic brook
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it gave me different answers

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i got 1 and -3

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from it

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when i used that

twilit lake
# mystic brook i got 1 and -3

but those are the zero's, x values when we substitute in we get zero
so (x-1) would be one zero, because we substitute in 1 we get 0

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and (x+3), because when we substitute in -3 we get 0

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so in the end we have (x-1)(x+3)

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as our factored form

mystic brook
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did i do something worng?

twilit lake
twilit lake
meager scaffoldBOT
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せんく(It's Quantum)

mystic brook
twilit lake
# mystic brook how was i supposed to use it?

the solutions you get from the quadratic formula will should be zero when substituted in into the factors. for example
if your solution is 3 and 2, then it would be (x-3) and (x-2) in factored form for that function because when we replace x with 3 and 2 respectively we get 0, which is the point

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so basically change the sign, i.e negative or positive for solutions, which is a way of looking at it.

mystic brook
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omg

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im not getting it

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sorry

twilit lake
mystic brook
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how 1 and -3

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turned into

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(x+3)(x-1)

twilit lake
# mystic brook how 1 and -3

1 and -3 are x values for when our function is 0.
So that implies that, that it should be true in it's factored form as well

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(x+3) becomes zero when x = -3

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and likewise, (x-1) becomes 0 when x = 1

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hence our factored form becomes, (x+3)(x-1)

mystic brook
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oh

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so im allowed to make them positive/negative no matter what

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?

twilit lake
mystic brook
mystic brook
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so so here im just supposed to turn it into -1 and 3 and continue it?

twilit lake
mystic brook
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im using this form

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wasnt i supposed to use it?

twilit lake
# mystic brook wasnt i supposed to use it?

that is a formula not a form. I could as well have said that our zero's or roots of the functions are 1 and -3, but we would have said the same thing if we wrote it like this (x-1)(x+3)

mystic brook
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so im changing the values since i would get 0 if i used those

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right?

twilit lake
dreamy saffron
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There's an easier way.

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What's (x - 1)^2?

young frigate
young frigate
# mystic brook idk where to start

or if u know how to factor out x-1

you already know -1 has a digit so find two numbers that multiply to -3 and add to 2. you know alread -1 has to be one so the other number can only be 3

Test:
-1 x 3 = -3
-1 + 3 = 2

So it will be simplified to (x-1) (x+3)/ (x-1)

Now divide both sides by x-1 and you will get x+3

Hence x = -3

Enjoy

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x= -3, enjoy

twilit lake
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@mystic brook factor

cosmic birch
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how is this a university question?