cos(x) ------ 3
d /cos(x)\ --|------| dx\ 3 /
The derivative of a constant times a function is the constant times the derivative of the function.
The derivative of cosine is negative sine:
So, the result is: −sin(x)3- \frac{\sin{\left(x \right)}}{3}−3sin(x)
The answer is:
-sin(x) -------- 3
-cos(x) -------- 3
sin(x) ------ 3