How do you find the axis of symmetry, graph and find the maximum or minimum value of the function #y = x^2 + 4x - 5 #?
Axis of symmetry
we first of all need to complete the square before we find the required information.
half the coefficient of x , square it; then add and subtract it
The bracket is now a perfect square
because the graph is
This minimum occurs at the vertex
so minimum occurs at
The axis of symmetry is the line through the vertex
(The scale of the graph is set to show intersection points - it won't look like this on graph paper!!!)