Answer:
(a) Increasing:
and Decreasing:
(b) The local minimum and maximum values are -16 and 16 respectively.
(c) The inflection points are 
Step-by-step explanation:
The function provided is:

(a)

Then, ![f'(x)=-16cos(x)sin(x)-16cos(x)=-16cos(x)[1+sin(x)]](https://tex.z-dn.net/?f=f%27%28x%29%3D-16cos%28x%29sin%28x%29-16cos%28x%29%3D-16cos%28x%29%5B1%2Bsin%28x%29%5D)
Note, 
Then,
for
.
Also
.
Thus, f (x) is increasing for,

And f (x) is decreasing for,

(b)
From part (a) f (x) changes from decreasing to increasing at
and from increasing to decreasing at
.
The local minimum value is:

The local maximum value is:

(c)
Compute the value of f'' (x) as follows:
![f''(x)=16sin(x)[1+sin(x)]-16cos^{2}(x)\\\\=16sin(x)+16sin^{2}(x)-16[1-sin^{2}(x)]\\\\=32sin^{2}(x)+16sin(x)-16\\\\=16[2sin(x)-1][sin (x)+1]](https://tex.z-dn.net/?f=f%27%27%28x%29%3D16sin%28x%29%5B1%2Bsin%28x%29%5D-16cos%5E%7B2%7D%28x%29%5C%5C%5C%5C%3D16sin%28x%29%2B16sin%5E%7B2%7D%28x%29-16%5B1-sin%5E%7B2%7D%28x%29%5D%5C%5C%5C%5C%3D32sin%5E%7B2%7D%28x%29%2B16sin%28x%29-16%5C%5C%5C%5C%3D16%5B2sin%28x%29-1%5D%5Bsin%20%28x%29%2B1%5D)
So,

And,

Thus, f (x) is concave upward on
and concave downward on
.
If
, then f (x) will be:

If
, then f (x) will be:

The inflection points are
.