Question

Can I get help with this

Answer 1

Answer:

The correct option is;

B) -6

Step-by-step explanation:

The given parameters are;

The line of symmetry of f(x) = The line of the reflection of g(x) over the y-axis

f(x) = 3·x² + b·x + c

From the given graph of g(x), we have;

The vertex point of g(x) = (-1, 8)

The line of symmetry is the line x = -1

The image of the reflection of (x, y) over the y-axis is (-x, y)

The image of the vertex of g(x) following a reflection across the y-axis is (1, 8)

Therefore;

The line of symmetry of the image of g(x) following a reflection over the x-axis is the line x = 1

The line (axis) of symmetry of a quadratic function is the line x = -b/(2·a), which is a line that always go through the vertex of the parabola

Where;

a = The coefficient of x²

b = The coefficient of 'x'

For f(x) = 3·x² + b·x + c, a = 3, and b = b

Given that f(x) and the image of g(x) have the same line of symmetry, we have;

The line of symmetry of f(x) is x = 1

Therefore, from the formula for the line of symmetry, we have;

x = -b/(2·a)

x = 1

By substitution, we have;

1 =  -b/(2·a)

∴ -2·a = b

Given that a = 3, we get;

-2 × 3 = -6 = b

b = -6