Question

For the graph below, what should the domain be so that the function is at least 300?

A.) x≥0
B.) -5≤x≤30
C.) 0≤x≤25
D.) All real numbers

Answer 1

Option C. 0≤x≤25

Explanation:

we know that

The function f(x) of the graph is a vertical parabola open down

If the function is at least 300

then

`f(x)\geq 300`

The solution is the shaded area above the solid line f(x)=300

In the graph plot f(x)=300 and find the value of x

The values of x are

`x=0, x=25`

see the attached figure

therefore

The interval is ------> [0,25]

All real numbers greater than or equal to zero and less than or equal to 25