Question

Find the verte of the quadratic function given below f(x) = (x-4) (x+2)

Answer 1

Vertex at (1,-9)

Explanation:

Expand the equation by using foil method.

You should get X^2+2x-4x-8

And then add the like terms.

X^2-2x-8

And use this formula to find the vertex.

X=b/2a

plug in the values

X=-2/2(1)

you should get x=1

Thats the one value.

For another one you have to plug in you X= (value which is 1) in the f(x) which now becomes f(1)

the answer is f(1)=-9