Question

Quadratic functions anyone?
h(x)=-x^2-6x-9
f(x)=2x^2+9x+4
g(x)=x^2+x-20

Answer 1

Do you just want those solved?

Answer 2

I can solve it but its gonna take a lil min

Answer 3

maybe lik 10 min

Answer 4

first those equations have to be a x and y not both x...are you sure those are the right equations

Answer 5

yes @lovingod786

Answer 6

@lovingod786

Answer 7

@wolf1728 Yeah..but I need to show a little work..

Answer 8

Ik im doing it rn

Answer 9

Ok so you're gonna have double arenthese like (x 3) (x 3)...all you have to do is figure out the signs like negative and positive to get the equation lik -x^2 -6x-9

Answer 10

nvm...ima just do it the long way

Answer 11

haha... I was confused for a second @lovingod786

Answer 12

so first youre gonna identify your A,B, and C in the equation....ax^2+bx+c=0

Answer 13

Then you're gonna plug those letters into the equation

Answer 14

would -x just be -1? @lovingod786

Answer 15

\[x=\frac{ -b+\sqrt{b^2 -4ac}}{ 2a }\]

Answer 16

No it wudnt...ur solving for x

Answer 17

so in the equation where it states -b..it would only b -b if your b from the original equation is positve.

Answer 18

but the b from the original is negative...

Answer 19

so therefore it wud b positve

Answer 20

But the B that is in the sqrt root wud b the original negative B

Answer 21

This is how your equation should look

Answer 22

\[x= \frac{ 6 + \sqrt{(-6^2) - 4 (-1)(-9)} }{2(-1)}\]

Answer 23

get it?

Answer 24

YES!!(:

Answer 25

You can finish it from here?

Answer 26

I will...try?

Answer 27

Oh and btw where the + is b4 he sqaure root...how I was taught was..its also a minus sign under the addition sign so you will come out with two answer and either or.

Answer 28

Lemme see you work ou tthe problem

Answer 29

The either or is basically the same thing but one you get the subtraction you solve for the addition with the same stuff

Answer 30

\[\frac{ a }{ b } + \frac{ a }{ b }\]

Answer 31

\[\frac{ a }{ b } - \frac{ a }{ b }\]

Answer 32

Thats basically the either or format

Answer 33

Do you have the answer??

Answer 34

no.. I have no idea what to do now @lovingod786

Answer 35

I thought I could but..

Answer 36

What happened

Answer 37

Where did you get stuck

Answer 38

I just don't know what to do...
I don't know where to start and what to start..

Answer 39

Ok just look...ima gonna do step by step.

Answer 40

ok! I will write this down so I can look later on too!

Answer 41

\[x = \frac{ -b + \sqrt{b^2 - 4ac} }{ 2a }\]

Answer 42

Wait...do you understand where the A,B, and C.come fromwith the original equation?

Answer 43

yes!

Answer 44

ok i will continue now

Answer 45

\[x= \frac{ 6 + \sqrt{-6^2 - 4(9)} }{ -2 }\]

Answer 46

\[x = \frac{ 6+ \sqrt{-6^2 - 36} }{ -2 }\]

Answer 47

\[x = \frac{ 6 + \sqrt{36-36} }{ -2 }\]

Answer 48

\[x = \frac{ 6 + 0 }{ -2 }\]

Answer 49

\[x = \frac{ 6 }{ -2 } = -3\]

Answer 50

THANK YOU! That helped a lot!

Answer 51

When I do the other problems (tomorrow, it's late), would I be able to check my work with you? @lovingod786

Answer 52

Yeah just tag me like you're doin now

Answer 53

I will get a notification

Answer 54

Will do!
So is that the final answer, -3?

Answer 55

Yeah

Answer 56

Yay! That was so much easier than I expected... You were very good at explaining! thank you!

Answer 57

You're welcome

Answer 58

does x=15.75 for b? @lovingod786

Answer 59

lol oh snap I didnt even plug inhold on

Answer 60

hah! it's ok!(:

Answer 61

\[h(x) = -x^2 -6x -9\]

Answer 62

\[h(-3)=-(-3)^2 -6(-3) - 9\]

Answer 63

\[h(-3) = -(9) + 18 + 9 \]

Answer 64

Answer should b 0

Answer 65

Dang it... so now what?

Answer 66

I think I am going to go to sleep and try again in the morning!!
for b: x=15.75
for c: I didn't understand @lovingod786
Good night!

Answer 67

thank you anyways!

Answer 68

I got the wrong answer hold on

Answer 69

You should follow PEDMAS

Answer 70

So it should be..

Answer 71

\[h(-3) = (3)^2 +18 -9\]

Answer 72

then so exponents so the equation wud b 9+9 = 18

Answer 73

I even checked with mathway

Answer 74

18 is the final answer for the equation h(18)

Answer 75

h(x)=-x^2-6x-9
testing the -3 answer
h(x) = -(-3^2) -6*-3 -9
h(x) = -9 +18 -9
h(x) =0
so -3 is a valid answer

Answer 76

lovingod786
you used the quadratic formula for equation (h)
x = [6 +-sq root (36 -36)] / -2
x = 6 +- sq root(0) / -2
-3 is one valid root
what is the other root?

Answer 77

What do you mean the other root? @wolf1728

Answer 78

Because since it is a zero you dont need two answers

Answer 79

Solving the equation with the quadratic formula:
x = 6 +- sq root(0) / -2
Notice there is a "+-" before the sq root.

Answer 80

Yes, so both answers are -3 and -3

Answer 81

There's no two answers for this...because all you are doing is subtracting and adding the zero so you could just leave it as -3 but if you want to write it like how you doing it then go right ahead

Answer 82

The only reason I am stating both answers is that teachers always insist upon the student giving BOTH answers (even if the answers are equal).

Answer 83

My bad...You don't plug intothe equation as I see...The answer you got where the formula contains a square root is the answer

Answer 84

It seems you were testing the -3 answer with the equation
h(−3)=(3)2+18−9
and then you say
18 is the final answer for the equation h(18)
Actually, you miscalculated in setting up
h(−3)=(3)2+18−9 it should be

h(−3)=-(-3)2 -(6*-3) −9
h(−3)= -9 +18 -9
h(-3) = 0

Answer 85

Yes, plugging the number into the equation is just the way to test if the answer is correct

Answer 86

I got that answer at first but then I plugged it into mathway to double check and they gave me 18 for the whole equation

Answer 87

Well at least we have the answer for the first equation :-)

Answer 88

Lol need help with the rest??

Answer 89

I think we should stop here and maybe have sophadof do a little work too.

Answer 90

ok

Answer 91

ok see ya

Answer 92

I am working on it!!!(: sorry for not responding, i was at work @wolf1728 @lovingod786

Answer 93

Here's the second quadratic equation
f(x)=2x^2+9x+4
with a, b and c put into the quadratic formula:
x= [-9 +-sq root(81 -4*2*4)] / 2*2

Can you solve it from here?