Question

The axis of symmetry for the graph of the function s1x) = 2x2 + bx + 10

2 + bx + 10 is x=6. What is the value of b?

Answer 1

b = -4

Explanation:

The formula for b is

-b

x = ------- and so -b = 2ax, or b = -2ax

2a

if the axis of symmetry is known, but we need b, substitute the given x and a values to find b:

b = -2(2) = -4

b = -4

The function is then y = 2x^2 - 4x + 10