Question

Three functions are given below: f(x), g(x), and h(x). Explain how to find the axis of symmetry for each function, and rank the functions based on their axis of symmetry (from smallest to largest).
f(x) = -4(x − 8)2 + 3

g(x) = 3x2 + 12x + 15

(graph attatched= h(x) )

Answer 1

Answer:

1. x=8 is the line of symmetry for f(x) = -4(x − 8)2 + 3

2. x=-2 is the line of symmetry of g(x) = 3x2 + 12x + 15

3. x=3 is the line of symmetry of h(x), shown in the graph.

Step-by-step explanation:

To find the line of symmetry of a vertical parabola (second degree polynomial), find the value of x that sets the squared term to zero.  This is a vertical line passing through the vertex of the second degree function.

1. f(x) = -4(x − 8)2 + 3

setting x=8 will give f(8) = 3, so x=8 is the line of symmetry

2. g(x) = 3x2 + 12x + 15

here, we need to complete the squares,

g(x) = 3x2 + 12x + 15

g(x) = 3(x^2+4x+5)

g(x) = 3(x^2 + 2(2x) +4 +1)

g(x) = 3((x+2)^2 +1)

So setting x=-2 will anihilate or cancel the squared term, therefore

x= -2 is the line of symmetry.

3. the curven shown in graph,

we see that the vertex is at x=3, so x=3 is the line of symmetry.