Question

What is the value of k?

Answer 1

k = 3

Explanation:

The vertex is (d, e)

for quadratic function: f(x) = ax² + bx + c we have:

d = -b/a and d = (x₁ + x₂)/2

a = 1, b = k, x₁ = -4, x₂=-2

so:

d = -b/a = -k/1 = -k and d = (x₁ + x₂)/2 = (-4-2)/2 = -3

-k = -3

k = 3