Final answer:
The roots of the quadratic function are x = -2 and x = -4. The vertex is at (3, f(3)).
Step-by-step explanation:
The given quadratic function is -x^2-6x-8.
To find the roots of the quadratic function, we can set it equal to zero and solve for x.
-x^2-6x-8 = 0
Factoring the quadratic equation gives us (x+2)(x+4) = 0.
Setting each factor equal to zero, we find that the roots are x = -2 and x = -4.
To find the vertex, we can use the formula x = -b/2a. In this case, a = -1 and b = -6.
Substituting the values of a and b into the formula gives us x = -(-6)/2(-1) = 3. So the vertex is at (3, f(3)).