Given:
The function is
[tex]f(x)=-x^2+4[/tex]
It defined on the interval -8 ≤ x ≤ 8.
To find:
The intervals on which the function is increasing and the interval on which decreasing.
Step-by-step explanation:
We have,
[tex]f(x)=-x^2+4[/tex]
Differentiate with respect to x.
[tex]f'(x)=-(2x)+(0)[/tex]
[tex]f'(x)=-2x[/tex]
For turning point f'(x)=0.
[tex]-2x=0[/tex]
[tex]x=0[/tex]
Now, 0 divides the interval -8 ≤ x ≤ 8 in two parts [-8,0] and [0,8]
For interval [-8,0], f'(x)>0, it means increasing.
For interval [0,8], f'(x)<0, it means decreasing.
Therefore, the function is increasing on the interval [-8,0] and decreasing on the interval [0,8].