Answer:
the vertex is (-2, 11)
Explanation:
F(x) = -2X^2 - 8X + 3 can be rewritten as -2(x^2 + 4x) + 3.
We complete the square of x^2 + 4x, obtaining x^2 + 4x + 4 - 4 = (x + 2)^2 - 4
and then we substitute this last result into F(x) = -2(x^2 + 4x) + 3:
F(x) = -2[ (x + 2)^2 - 4 ] + 3, which simplifies to:
F(x) = -2(x + 2)^2 + 8 + 3, or F(x) = -2(x + 2)^2 + 11
Comparing this to the vertex equation (x + h)^2 + k, we see that h must be -2 and k must be 11.
Thus, the vertex is (-2, 11).