Find the vertex of the following function.
f(x) = -2x2 - 4x
Enter your answer as an ordered pair, example: (1, -2)

Question

Find the vertex of the following function.
f(x) = -2x2 - 4x 
Enter your answer as an ordered pair, example: (1, -2)

anonymous · Answer

$$y=-2x^{2}-4x$$
We need to derive:
$$y^{'}=-4x-4$$
Set the derivative equal to 0:
$$-4x-4=0$$
Solve for x:
$$-4x=4$$
$$x=-1$$
Plug into original problem to find y:
$$y=-2(-1)^{2}-4(-1)$$
$$y=-2+4$$
$$y=2$$
So the ordered pair is:
(-1,2)

anonymous · Answer

ty u actully showed how to solve it

anonymous · Answer

You're welcome. Always best to learn how to solve the problems. The test won't have someone looking over your shoulder to help, so happy to explain :)