Mister Exam

Derivative of cos(1/x)

Function f() - derivative -N order at the point
v

The graph:

from to

Piecewise:

The solution

You have entered [src]
   /1\
cos|-|
   \x/
$$\cos{\left(\frac{1}{x} \right)}$$
cos(1/x)
Detail solution
  1. Let .

  2. The derivative of cosine is negative sine:

  3. Then, apply the chain rule. Multiply by :

    1. Apply the power rule: goes to

    The result of the chain rule is:


The answer is:

The graph
The first derivative [src]
   /1\
sin|-|
   \x/
------
   2  
  x   
$$\frac{\sin{\left(\frac{1}{x} \right)}}{x^{2}}$$
The second derivative [src]
 /              /1\\ 
 |           cos|-|| 
 |     /1\      \x/| 
-|2*sin|-| + ------| 
 \     \x/     x   / 
---------------------
           3         
          x          
$$- \frac{2 \sin{\left(\frac{1}{x} \right)} + \frac{\cos{\left(\frac{1}{x} \right)}}{x}}{x^{3}}$$
The third derivative [src]
              /1\        /1\
           sin|-|   6*cos|-|
     /1\      \x/        \x/
6*sin|-| - ------ + --------
     \x/      2        x    
             x              
----------------------------
              4             
             x              
$$\frac{6 \sin{\left(\frac{1}{x} \right)} + \frac{6 \cos{\left(\frac{1}{x} \right)}}{x} - \frac{\sin{\left(\frac{1}{x} \right)}}{x^{2}}}{x^{4}}$$
The graph
Derivative of cos(1/x)