# Is #f(x)= sin(x+(3pi)/8) # increasing or decreasing at #x=pi/12 #?

##### 1 Answer

Feb 19, 2017

The function

#### Explanation:

The growth or decrease of a function is given by the sign of its first derivative. If the derivative is positive, the function is increasing, whereas if the derivative is negative, the function will be decreasing.

Therefore, we first calculate the derivative of

and then we substitute the value of

Given that:

then

and, therefore, the function is increasing at