# Is #f(x)= cos(x+(pi)/4) # increasing or decreasing at #x=pi/3 #?

##### 1 Answer

Nov 5, 2016

#### Explanation:

Whether a function is increasing or decreasing at a point depends on the value of its derivative at that point.

If derivative is positive, function is increasing and if it is negative, function is decreasing.

As

and at

As

Hence,