/ /1\\
-cos|x*sin|-||
\ \x//
-cos(x*sin(1/x))
The derivative of a constant times a function is the constant times the derivative of the function.
Let .
The derivative of cosine is negative sine:
Then, apply the chain rule. Multiply by :
Apply the product rule:
; to find :
Apply the power rule: goes to
; to find :
Let .
The derivative of sine is cosine:
Then, apply the chain rule. Multiply by :
Apply the power rule: goes to
The result of the chain rule is:
The result is:
The result of the chain rule is:
So, the result is:
Now simplify:
The answer is:
/ /1\ \ | cos|-| | | \x/ /1\| / /1\\ |- ------ + sin|-||*sin|x*sin|-|| \ x \x// \ \x//
2
/ /1\ \ /1\ / /1\\
| cos|-| | sin|-|*sin|x*sin|-||
| \x/ /1\| / /1\\ \x/ \ \x//
|- ------ + sin|-|| *cos|x*sin|-|| - --------------------
\ x \x// \ \x// 3
x
/ /1\ \
3 | cos|-| |
/ /1\ \ /1\ / /1\\ /1\ / /1\\ | \x/ /1\| / /1\\ /1\
| cos|-| | cos|-|*sin|x*sin|-|| 3*sin|-|*sin|x*sin|-|| 3*|- ------ + sin|-||*cos|x*sin|-||*sin|-|
| \x/ /1\| / /1\\ \x/ \ \x// \x/ \ \x// \ x \x// \ \x// \x/
- |- ------ + sin|-|| *sin|x*sin|-|| + -------------------- + ---------------------- - ------------------------------------------
\ x \x// \ \x// 5 4 3
x x x