Consider the function fx 2x2 4x2 A Determine the vertex of t
Consider the function f(x) -2x2 +4x-2
A) Determine the vertex of the graph of this function
B) Write the function in the form f(x)= a(x-h)2 +k
C) Explain the shifts or reflections of the graph of y=f(x), relative to y=x2
D) Determine the value of x, that results in the maximum value of f(x)
E) What is the maximum value of the function?
F) What are the x intercepts of the graph of the function?
G) For what intervals in the domain of f, is f(x) < 0?
H) For what intervals in the domain of f, is f(x) > 0?
Solution
f(x)= -2x^2 +4x-2
a) Vertex: x= -b/2a = -(4/2*(-2)) =1
Plug x= 1 in f(x) = -2 +4 -2 = 0
Vertex = ( 1, 0)
b) f(x) = -2( x^2 -2x+ 1 -1) -2
= -2(x -1)^2+ 2 -2
f(x) = -2(x-1)^2
c) w.r.t to f(x) = x^2
f(x) is horizontally shifted right by 1 unit y = (x -1)^2
f(x) is vertically shifted by 2 units y = 2( x-1)^2
f(x) is reflected along x axis y = -2(x -1)^2
d) The x coordinate gives the maximum vale x= 1
e) Maximum value at x= 1 f(x) =0
f) X intercept: y=0 ; (x-1)^2 =0---> x =1
