#help me simplify this
79 messages · Page 1 of 1 (latest)
Factorise the numerator
There are two ways
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
Let's go with the factoring method because it's less tedious
could u show me this method
Yes
I'll show the quadratic formula too, so you know the difference
ok
せんく(It's Quantum)
great it works
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)
せんく(It's Quantum)
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.
せんく(It's Quantum)
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 \
yea i know that one
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
and (x+3), because when we substitute in -3 we get 0
so in the end we have (x-1)(x+3)
as our factored form
did i do something worng?
well you didn't get the wrong zero's or roots. U just used it wrong when changing it into factored form
$\frac{x^2+2x-3}{x-1}$ would now be $\frac{(x-1)(x+3)}{x-1}$
せんく(It's Quantum)
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
so basically change the sign, i.e negative or positive for solutions, which is a way of looking at it.
Tell where it's confusing and I'll try to clear it up
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
(x+3) becomes zero when x = -3
and likewise, (x-1) becomes 0 when x = 1
hence our factored form becomes, (x+3)(x-1)
well that is how it seems, remember that we should be able to get their factored form to 0 when replacing the x with the solutions from the quadratic formula
this goes for other calculations related to this?
Verily
so so here im just supposed to turn it into -1 and 3 and continue it?
You are missing the point, you are not changing the solutions you are just writing it in another form, this case being factored form, where the factors when we replace the solutions we get 0.
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)
oooh
so im changing the values since i would get 0 if i used those
right?
Yeah
u have to use long diviosn
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
x= -3, enjoy
Divide both sides of what?
@mystic brook factor
how is this a university question?