Question

Express in standard form

Answer 1

I am having trouble because of the 2 infront of the X2

Answer 2

\[f(x)+6=2x^2+x\]
Is what our teacher said step 1 was.

Answer 3

whats the standard form ?

Answer 4

\[f(x)=a(x-h)^2+k\]

Answer 5

Where -h, k is the vertex.

Answer 6

ok, wiki says otherwise, but some books refer to that as standard form...

so, you want to complete the square ,right ?

Answer 7

Right.

Answer 8

2 x^2+x
factor out the 2 first,
hiw will u do it ?

Answer 9

That is where I am stuck. 2(x^2 + ___) but i am not sure for the ____.

Answer 10

ok,
\(\Large 2x^2+x = 2 (x^2+\dfrac{1}{2})\)

Answer 11

i meant 1/2 x

Answer 12

That makes sense! So then I say (1/2)^2, but it will be (X+1/2)^2?

Answer 13

right!
\(\large 2(x+1/2)^2\)
be careful on what you add both sides..

Answer 14

Would it be +1?

Answer 15

gurr, (x+1/2)^2-7

Answer 16

expand that and check!
2 (x+1/2)^2-7

you forgot the 2 too :P

Answer 17

does 2-7 = -6 ?

Answer 18

I am off 1.

Answer 19

Needs to be 8.

Answer 20

\[2(x+\frac{ 1 }{ 2 })^2 -8\]

Answer 21

2 (2*1/2 x) = 2x
the 'x' term is off too....

Answer 22

\(\Large 2x^2+x = 2 (x^2+\dfrac{x}{2}+\dfrac{1}{16}-\dfrac{1}{16})\)

Answer 23

the co-efficient of 'x' is 1/2
half of that is 1/4
square of that = 1/16
so actually (x+1/4)^2

Answer 24

So \[(x+1/4)^2 -8 \]
Or is that off too?

Answer 25

don't haste, first tell me whether you got that ?

Answer 26

Oh, well from the first part it was f(x)+6=2x2+x
So now I need to do something with that 1/16.

Answer 27

\(\Large 2x^2+x-6 = 2 (x^2+\dfrac{x}{2}+\dfrac{1}{16}-\dfrac{1}{16})-6 \\ \Large =2(x+1/4)^2-1/8-6\)
now calculate the constant part

Answer 28

Ohh! I forgot the 2. That makes it 1/8. So it is -49/8

Answer 29

yup

Answer 30

Thank you much.

Answer 31

welcome ^_^

Answer 32

How would I find the x intercept without using my calculator? Plug in 0 to what we just found?

Answer 33

x intercept mean f(x)=0
y intercept means x=0

Answer 34

So 0=2(x+1/4)^2 -49/8?

Answer 35

yeah, but you know thats also = x^2+x-6
so, that = 0 is the simplied form

Answer 36

2x^2+x-6

Answer 37

ahh, FOIL!

Answer 38

maybe not..

Answer 39

2x^2+x-6 = 0 is easily factorable
2 numbers with sum = 1, product = -12 are ?

Answer 40

(x+2)(2x-3)

Answer 41

good :)
that =0 will give you 2 intercepts.

Answer 42

So x=-2 and 3/2

Answer 43

x -intercepts are points with y=0
so,
-2,0 and 3/2,0
:)

Answer 44

The Y int would be -6, right?

Answer 45

yes

Answer 46

0,-6

Answer 47

Thanks for saving me 10 points!

Answer 48

i thought i was saving your bus from being blasted :P

Answer 49

As always! Actually you saved it from blowing its dual rear tires this time.

Answer 50

lol, welcome ^_^