True! A y value can have 2 x values, but a x value can have 2 y values
CF = CD + DF (since D is simply a point on the line, and C to that point added onto F to that point is CF), so 4y-9+2y-7=14. Adding it up, we get 6y-16=14 and adding by 16 we get 30=6y. Dividing both sides by 6, we get y=5. Plugging that into DF, we get 10-7=DF=3

then the domain of (f•g)(x) is {-1, 1, 3/2}
Given:
Consider the height of the rocket, in feet after x seconds of launch is

To find:
The time at which the rocket will reach its max, to the nearest 100th of a second.
Solution:
We have,

It is a quadratic polynomial with negative leading coefficient. So, it is a downward parabola.
Vertex of a downward parabola is the point of maxima.
To find the time at which the rocket will reach its max, we need to find the x-coordinate of the vertex.
If a quadratic function is
, then the vertex is

Here,
.
So,



So, x-coordinate of the vertex is 4.75.
Therefore, the rocket will reach its max at 4.75 second.