Question

m

Answer 1

I know it will be a max value since it's a negative parabola..

Answer 2

can you differentiate?

Answer 3

yes a maxim

Answer 4

I also think it is either max of 9 or -9

Answer 5

but not confident in my arithmetic here

Answer 6

ok... do you know how to differentiate..?

or find the line of symmetry of a parabola..?

Answer 7

i do not :(

Answer 8

ok... here is the easy way....

every parabola has a line of Symmetry. The max or min value is on the line of symmetry.

to find the line of symmetry for a parabola

\[y = ax^2 + bx + c\]

use

\[x = \frac{-b}{2a}\]

using your question

a = -1 and b = 2

the line of symmetry is

\[x = \frac{-2}{2 \times -1}\]

so the line of symmetry is

x = 1

does this make sense