Answer:
How do you find the sum of factors of a quadratic equation?
Let r and s be the factors for the quadratic equation such that x^2+Bx+C=(x−r)(x−s) where sum of factors (r+s)=−B and the product of factors rs = C r = -2 - u s = -2 + u Two numbers r and s sum up to -4 exactly when the average of the two numbers is \frac{1}{2}*-4 = -2.
How do you solve a quadratic equation?
Quadratic equations such as this one can be solved by completing the square. In order to complete the square, the equation must first be in the form x^{2}+bx=c.
Step-by-step explanation:
The given graph is a downward parabola.
The roots of the equation is -2 and -8, and the vertex is (-5,7).
The general root form of parabola will be,
a(x-(-2))(x-(-8))=a(x+2)(x+8).
The value of a can be determined from the coordinate of vertex,

Thus, the required quadratic is,

The value of f(-6) can be determined as,

Thus, the requried value of f(-6) is 6.22.