Question

Write the quadratic function in the form f(x)=a−(x-h)^ 2+k . Then, give the vertex of its graph.f(x)=-2x^2+8x-5

Answer 1

\(f(x) = ax^2+bx+c\) is the same thing as \(f(x) =a(x+\dfrac{b}{2a})^2+c-a(\dfrac{b}{2a})^2 \)

Answer 2

so i just plug it in?

Answer 3

isn't the x point for the vertex -b/2a?

Answer 4

hi!!

Answer 5

this is not that hard
it is \[f(x)=-2x^2+8x-5\]right?

Answer 6

yes

Answer 7

you want to write it as
\[f(x)=a(x-h)^2+k\] all you need is \(h\) and \(k\)

Answer 8

since evidently \(a=-2\)

Answer 9

to find \(h\) compute \(-\frac{b}{2a}\) which, in your case, is \(-\frac{8}{2\times (-2)}\)

Answer 10

what do you get ?

Answer 11

is it -8/4x? and simplify so its -2x?

Answer 12

or is it 2/x

Answer 13

it's just 2 Kimes

Answer 14

oh opps i mistaken x and a variable

Answer 15

as*

Answer 16

@Kimes yes just plug things :)