Question

Can anyone find the coordinates of the vertex of the graph of y=2x^2+4x-2

Answer 1

y=2x^2+4x-2 is in the form y=ax^2+bx+c

where

a = 2
b = 4
c = -2

Answer 2

Plug a = 2 and b = 4 into the formula

x = -b/(2a)

to get the x coordinate of the vertex

Answer 3

Tell me what you get

Answer 4

\(\bf \textit{vertex of a parabola}\\ \quad \\
y = {\color{red}{ 2}}x^2{\color{blue}{ +4}}x{\color{green}{ -2}}\qquad\quad
\left(-\cfrac{{\color{blue}{ b}}}{2{\color{red}{ a}}}\quad ,\quad {\color{green}{ c}}-\cfrac{{\color{blue}{ b}}^2}{4{\color{red}{ a}}}\right)\)

as jim_thompson5910 suggested

Answer 5

I think it equals -1 Jim Thompson

Answer 6

Is that the answer?

Answer 7

x = -1 is the x coordinate of the vertex

that's half of your answer

Answer 8

you need the y coordinate

your answer will be of the form (x,y)

Answer 9

So is it (0,-1)

Answer 10

plug x = -1 into y=2x^2+4x-2

Answer 11

Oh so y=-4

Answer 12

Right?

Answer 13

Or wrong :(

Answer 14

ahemm

Answer 15

y=2x^2+4x-2

y=2(-1)^2+4(-1)-2

y = -4

so you are correct

Answer 16

the vertex is therefore the point (-1,-4)

Answer 17

Thanks Jim I really appreciate it and I also thank you too Jdode

Answer 18

you're welcome