Question

Identify the axis of symmetry for the quadratic function.

y = x^2 + 2x – 3

Answer 1

The x coordinate of the vertex is x = -b/2a. Since the axis of symmetry is a vertical line that passes through the vertex, that is also the equation of the axis of symmetry.

Answer 2

So it would be -2/2(1) , then -2/2 ?

Answer 3

So it would be x = -2/2
x=-1

Answer 4

some how i got (1,-2) let me redo mine..

Answer 5

but how did it become negative ?

Answer 6

http://formula.algebra.com/cgi-bin/plot-formula.mpl?expression=drawing%28500%2C500%2C-10%2C10%2C-10%2C10%2C%0D%0Agrid%281%29%2C%0D%0Agraph%28500%2C500%2C-10%2C10%2C-10%2C10%2C+x%5E2-2x-1%29%2C%0D%0Acircle%28-1%2C2%2C0.05%29%2C%0D%0Acircle%28-1%2C2%2C0.08%29%2C%0D%0Acircle%28-1%2C2%2C0.10%29%2C%0D%0Acircle%280%2C-1%2C0.05%29%2C%0D%0Acircle%280%2C-1%2C0.08%29%2C%0D%0Acircle%280%2C-1%2C0.10%29%2C%0D%0Acircle%281%2C-2%2C0.05%29%2C%0D%0Acircle%281%2C-2%2C0.08%29%2C%0D%0Acircle%281%2C-2%2C0.10%29%2C%0D%0Acircle%282%2C-1%2C0.05%29%2C%0D%0Acircle%282%2C-1%2C0.08%29%2C%0D%0Acircle%282%2C-1%2C0.10%29%2C%0D%0Acircle%283%2C2%2C0.05%29%2C%0D%0Acircle%283%2C2%2C0.08%29%2C%0D%0Acircle%283%2C2%2C0.10%29%0D%0A%29&x=0003

Answer 7

The graph would look like this?

Answer 8

b=2, therefore -b = -2

Answer 9

http://www.wolframalpha.com/input/?i=y+%3D+x^2+%2B+2x+%E2%80%93+3

Answer 10

Oooooh okay I see now

Answer 11

Thank You!(: I realize how to do it now!

Answer 12

yw