F(x)=-x^2+6x+3
What is the maximum y-value? Y=

Question

F(x)=-x^2+6x+3
What is the maximum y-value? Y=

directrix · Answer

Look at this dominant term: -x^2 

-x^2 = negative (x^2). --> This term will never have a positive value.
The largest it can be is zero.

The maximum value of the function will occur where the dominant term -x^2 is a maximum. That is 0.

So, find the y that goes with x when x is 0.

anonymous · Answer

I am lost. I'm sorry.

directrix · Answer

If that explanation does not make sense, you can find the coordinates of the vertex of the parabola. The maximum value of the function is the y value of the coordinates of the vertex.

directrix · Answer

Do you know how to find the vertex of a parabola. @jrsyshur

anonymous · Answer

the vertex is the tip right? 3,12?

directrix · Answer

|dw:1374706700160:dw|