Question

Fan & Medal! Please help me
What is the axis symmetry of Y=-x^2+x-7?

Answer 1

Use the formula x= -b/2a.

Answer 2

The problem is set up like this....
Y=-x^2+x-7
Y=ax^2 +bx +c

Answer 3

When you use the quadratic formula, there is a term, \(x=\cfrac{-b}{2a}\pm~something\). This give you a hint because the plus or minus part tells you that \(x=\cfrac{-b}{2a}\) is right in the middle; hence, is the axis of symmetry.

Note a=-1, b=1 and c=-7 in your equation.

http://en.wikipedia.org/wiki/Quadratic_formula