Question

How do you find the quartic function that has its only two real zeros as x = -1 and x= -3? @mathmale

Answer 1

you can write the roots as (x+1) and (x+3)
f(x)=(x+1)(x+3)
expand the parenthesis, and you get
f(x)=x^2+4x+3

Answer 2

Do you write it with q(x) on the end as well? @SolomonZelman

Answer 3

Doesn't really matter, it's q(x) or f(x)
q(x) or f(x) is just saying it's a function

Answer 4

So to solve it out it would read f(x) = (x+1)(x+3)(x+1)?

Answer 5

Then you would factor and simplify?

Answer 6

yeah, but it's f(x)=(x+1)(x+3)
without the last (x+1)

Answer 7

But that doesn't give me enough to work with. What you said doesn't match my choices.

Answer 8

I found the answer but I just substituted the -1 and -3 into all of the equation. I still want to know how to do it if I were to not have multiple choice.

Answer 9

@crystalrock ?

Answer 10

yea?

Answer 11

Do you know how to solve?

Answer 12

no, sorry. I am horrible at math

Answer 13

Oh, okay..

Answer 14

@nincompoop Could you help?

Answer 15

do you know this formula

x^2 +Sx +P =0

where S = x_1 +x_2
and P = x_1 *x_2

for x_1 and x_2 roots of an quadratic

Answer 16

do you understand it ?

Answer 17

I don't believe I do.. I may have seen it a little differently though

Answer 18

so x_1 = -1 and x_2 = -3

continue it please

Answer 19

x^2 + x(x _ 1 + x _ 2) + x_1 * x_2 ??

Answer 20

Before we do this may I ask you a quick question about a different problem?

Answer 21

sorry i have missed an ---- there is minus Sx the midle term

so

x^2 -Sx +P =0

Answer 22

May I ask my other question?

Answer 23

ok i will try answer it ,than i can

Answer 24

Can you find the two real zeros for an equation when the equation doesn't have an "a"?

Answer 25

All real zeros - not two.. sorry.

Answer 26

Or do you just make "a" 1 because there is nothing there?

Answer 27

how you think it ? because a exist allways

when not is there nothing so than a = 1

yes

Answer 28

Okay so if you had and equation like this; y = (x-h) + k would would make it into this; y = 1(x-h) + , right?

Answer 29

+k on the end of the second equation - sorry

Answer 30

yes but why is this importantly ?

Answer 31

The question on general or involving the equation?

Answer 32

I had another question I had to do but hand't know to simply put 1 as "a" when "a" was missing.

Answer 33

write it here now please

Answer 34

Okay, this is the equation dealing with my question about "a".

Answer 35

Is that okay?

Answer 36

yes i think is right but we dont make never nothing with this 1

not is necessary writing there wnen you wann solve an exercise like this

Answer 37

Oh, okay. Can I leave it though?

Answer 38

because you know sure that 7/1 = 7

Answer 39

Yes, okay. I wrote the last answer as x = 3square root 7 + 12

Answer 40

Thank you for your help.

Answer 41

ok

but attention this not is square root

this has a name like cuberoot

Answer 42

because squarroot has indice 2

Answer 43

Oh i did not know that, thank you.

Answer 44

yw

my pleasure

good luck


bye

Answer 45

Bye. And thanks again.

Answer 46

How do you find the quartic function that has its only two real zeros as x = -1 and x= -3? I think you mean "quadratic function." If the function is truly quadratic, its highest x power is x^2. We want to find the quadratic function that has real zeros {-1,-3).

Represent this function as y=(x-[-1])(x-[-3]).
That reduces to y=(x+1)(x+3).
Expand this using the "foil" method.
Write the result in the form y=ax^2 + bx + c.

Answer 47

Hello, @mathmale thank you for this. I got what I need for that problem but if you should think of a trick to easily find factors of 400 that equal -40 I would be very appreciative! I can't seem get the right numbers.

Answer 48

Hi, Nicole! If these two factors of 400 equal -40 when added together, ... Nicole, did you want to finish this problem or work on a new one? it's up to you.

Answer 49

I would like to work a new one. I'll open a new post.

Answer 50

Great. Please do!