What are the coordinates of the vertex f(x)=2(x+1)(x+3)

Step-by-step explanation:

There are many methods to find the vertex of a quadratic function. The method that I will show you is by using the roots of the function

In the case of this function, the roots are ..

The vertex of a function will always be directly between these roots. The number that is directly between -1 and -3 is -2. This means that the x-value of our vertex is -2.

Now that we have the x-value, we can plug this into the function in order to get our y-value.

We have found that our y-value is -2. This means that the coordinates of the vertex are

d. 9

step-by-step explanation:

the answer is 15% decrease