Question

Need help finding the quartic function with only two real given x=-1 and x=-3

Answer 1

(x+1)(x+3) = x^2 + 3x + x + 3
x^2 + 4x + 3

Answer 2

how do I find the answer

Answer 3

isnt that the answer that I gave

Answer 4

doesnt match any that they give

Answer 5

is it quadratic or quartic?

Answer 6

y=x^4-4x^3-4x^2-4x-3
y=-x^4+4x^3+4x^2+4x+3
y=x^4+4x^3+3x^2+4x-4

Answer 7

quartic function

Answer 8

do you know how to do synthetic division?

Answer 9

no we are learning but I dont understand it

Answer 10

its easy!
check one by one: first x=-1 y=x^4-4x^3-4x^2-4x-3
-1) 1 -4 -4 -4 -3
-1 5 -1 5
--------------------
1 -5 1 -5 2

Answer 11

would it be y=x^4+4x^3+3x^2+4x-4

Answer 12

so y=x^4-4x^3-4x^2-4x-3 -----> u can eliminate this

Answer 13

lets check

Answer 14

i am sorry it si hard to do division on here!

Answer 15

can you explain how you got the numbers in the first one you did

Answer 16

ok first you gave me two real zeros: x= -1 and x= -3
I took the first zero x = -1

Answer 17

and then put it in divisor's place

Answer 18

then, the numbers after the parentheses are the coefficients of the terms of one of the choices you gave me, following me?

Answer 19

i think so for like the one i picked it would be
-1[1 4 3 4 4 but not sure what the numbers on bottom would be

Answer 20

the last 4 would be negative cuz its in the equation

Answer 21

-1) 1 4 3 4 -4

Answer 22

Yea I seen I made that mistake after I sent it

Answer 23

yeah there, so far you good?

Answer 24

but how did you get the numbers on bottom

Answer 25

ok i will tell you but before that let me tell you one more thing when lining up the coefficients.....for the equation we picked it has all the terms from degree 4, not missing a degree in the middle! But what if its like x^4 + x^2 + 3? what would you do then?

Answer 26

would they both be 1 1 3

Answer 27

no! zero would take place in the missing places
1 0 1 0 3

Answer 28

okay I see I was putting 1s for the xs

Answer 29

no no, I meant x^4 + x^2 + 3
it would be x^4 + 0x^3 + x^2 + 0x + 3
I was talking about those zeros

Answer 30

yea i see that i knew what you meant after i put mine cause you have to have 5 numbers

Answer 31

yes

Answer 32

now those very bottom numbers:

-1) 1 4 3 4 -4
0
---------------------

First you bring down the first coefficient down, imaging that theres a zero under the first 1

Answer 33

ok

Answer 34

then add 1 + 0
-1) 1 4 3 4 -4
0
-----------------------
1
then multiple the bottom 1 with the divisor, which in this case is -1
1(-1) = -1
-1) 1 4 3 4 -4
0 -1
----------------------------
1
the product goes int he middle line after the 0

Answer 35

am i confusing you?

Answer 36

not yet Im following

Answer 37

ok, then you would the same with 4 and -1 as you did with 1 and 0: add 4 and -1

Answer 38

3

Answer 39

the answer will take place in the bottom line after 1

Answer 40

yes

Answer 41

then you multiple 3 with the divisor, which is -1 and youll get -3
-3 will take place under the coefficient 3 in the middle line

Answer 42

want me to go on?

Answer 43

stop me whn u get confused, kay?

Answer 44

if you would please

Answer 45

so under the -4 it would be 4

Answer 46

then add 3 and -3 we will get 0, which will take its place in the bottom line

Answer 47

so far

-1) 1 4 3 4 -4
0 -1 -3 -1
---------------------------------
1 3 0

Answer 48

good?

Answer 49

yea I had a wrong number on the top line

Answer 50

ok then you add 4 and -1, which is 3
this 3 will take place in the bottom line after 0

Answer 51

then we multiply the 3 with the divisor, -1 and the answer is -3

Answer 52

ok now im lost

Answer 53

-1) 1 4 3 4 -4
0 -1 -3 -1
-------------------------
1 3 0 3

Answer 54

wait a sec! brb!

Answer 55

how come you dont add -4 to -1 and add to middle row

Answer 56

are u talking about the coeffiecient -4?

Answer 57

yea

Answer 58

we havent gotten there yet!!

Answer 59

oh sorry

Answer 60

its ok

Answer 61

-1) 1 4 3 4 -4
0 -1 -3 -1 -3
----------------------------
1 3 0 3

Answer 62

following?

Answer 63

how did you get -3

Answer 64

whats the last number on the bottom line?

Answer 65

it is 3 right? so I multiplied it with -1 and I got -3 which put in the middle line under -4

Answer 66

get it?

Answer 67

yea

Answer 68

then you add -4 and -3, and we get -7

Answer 69

whenever we get a number instead of zero in the bottom, we got -7, so its not a zero for that equation

Answer 70

doing ok?

Answer 71

i think so

Answer 72

here we got -7, but the question says that the function has to include x = -1 right? suppose this x = -1 is the zero/root/xint, we would have gotten zero instead of -7

Answer 73

ok

Answer 74

we can take that option out

Answer 75

ok

Answer 76

do the same with the other 2 equations and let me know

Answer 77

ok I will

Answer 78

i am going to look around, call me after u r done! :)

Answer 79

ok

Answer 80

not sure if Im going in the right direction
-1 1 4 3 4 -4
-2 3 -3

Answer 81

hey! we already did that!!

Answer 82

check the other 2 equations!

Answer 83

I thought we did the one that was y=x^4+4x^3+3x^2+4x-4 and I was doing y=-x^4+4x^3+4x^2+4x+3

Answer 84

I will finish tomorrow gotta get up early

Answer 85

want me to tell u the answer

Answer 86

y=-x^4+4x^3+4x^2+4x+3

Answer 87

thats the answer!! :)

Answer 88

ok!! Sorry if kept u late!! I am also studying the same

Answer 89

oh, you will get it, just practice more!! u will get it for sure!! :) :) :)

Answer 90

nope, but I learnt all that by myself when I was homeschooled 2 years ago

Answer 91

my home teacher was an airhead

Answer 92

very stupid that I taught him

Answer 93

awww.....hope ur family gets better soon!! but did you go to school before? what grade are you in btw?

Answer 94

same situation here.....everyone in my family caught virus including me

Answer 95

oh ok!! Call me whenever you need help with other subjects!! I will see what I can do!!! started college this year!! graduated from highschool in 2011!!

Answer 96

we got many things in common, I was home schooled when I was in 11th grade!! Coool!!

Answer 97

oh raelly? its really nice of you to help 'em!! I was sick at the time so i had to be home schooled

Answer 98

no problem! :) night!! take care!!! :))