1. ## standard form

if you are given the vertex(-3,4) and lets say the information of the parabola is stretched by -2

i know the vertex form is y=-2(x+3)+4

but what is the standard form?

thanks

2. Originally Posted by william
if you are given the vertex(-3,4) and lets say the information of the parabola is stretched by -2

i know the vertex form is y=-2(x+3)+4

but what is the standard form?

thanks
Expand the turning point form.

3. Originally Posted by mr fantastic
Expand the turning point form.
y=-2x-6+4...?

4. Originally Posted by william
y=-2x-6+4...?
Doesn't the equation of a parabola contain a squared term? (I had assumed your original post was missing it due to a typo).

5. Originally Posted by mr fantastic
Doesn't the equation of a parabola contain a squared term? (I had assumed your original post was missing it due to a typo).
$y=-2(x+3)^2+4$

you are very right

$y=-2x^2+9x+4...?$

6. Originally Posted by william
$y=-2(x+3)^2+4$

you are very right

$y=-2x^2+9x+4...?$
no.

$(x+3)^2 \neq x^2 + 9$

7. Originally Posted by skeeter
no.

$(x+3)^2 \neq x^2 + 9$
you're right $(x+3)^2=x^2+6x+9$ so is it $y=-2x^2+6x+9$

8. Originally Posted by william
you're right $(x+3)^2=x^2+6x+9$ so is it $y=-2x^2+6x+9$
No! Please concentrate on getting the algebra correct. Write out all the steps. Don't take short cuts.

$y=-2(x+3)^2 + 4 = -2(x^2 + 6x + 9) + 4 = -2x^2 - 12x - 18 + 4 = -2x^2 - 12x - 14$.

9. Originally Posted by mr fantastic
No, Please concentrate on getting the algebra correct. Write out all the steps. Don't take short cuts.

$y=-2(x+3)^2 + 4 = -2(x^2 + 6x + 9) + 4 = -2x^2 - 12x - 18 + 4 = -2x^2 - 12x - 14$.
thanks