Find the coordinates of the vertex and the axis of symmetry
Find the coordinates of the vertex and the axis of symmetry of the graph of the equation. Use (-b/2a, f(-b/2a)) to find the vertex. (Simplify the coordinates of the vertex completely.) See Example 8. (Objective 7) f(x) =-2x^2 - 4x + 4 vertex (x, y) = () axis of symmetry Graph the equation.
Solution
For a quadratic function in standard form, f(x) = ax2+bx+c,
the axis of symmetry is x = b/2a.
Given that f(x) = -2x2+4x+4
a = -2, b= 4, c=4
axis of symmetry:
axis of symmetry is x = -b/2a= -4/2.-2 = 1
x =1
Therefore,
axis of symmetry is x = 1
vertex:
Given that f(x) = -2x2+4x+4
vertex = (-b/2a, f(-b/2a))
f(-b/2a) = f (1) = -2.12 + 4.1 + 4 = 6
-b/2a = 1
Therefore,
vertex = (1,6)
