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1/(4+x^2)

Integral of 1/(4+x^2) dx

Limits of integration:

from to
v

The graph:

from to

Piecewise:

The solution

You have entered [src]
  1          
  /          
 |           
 |    1      
 |  ------ dx
 |       2   
 |  4 + x    
 |           
/            
0            
011x2+4dx\int\limits_{0}^{1} \frac{1}{x^{2} + 4}\, dx
Integral(1/(4 + x^2), (x, 0, 1))
Detail solution
We have the integral:
  /         
 |          
 |   1      
 | ------ dx
 |      2   
 | 4 + x    
 |          
/           
Rewrite the integrand
  1            1       
------ = --------------
     2     /     2    \
4 + x      |/-x \     |
         4*||---|  + 1|
           \\ 2 /     /
or
  /           
 |            
 |   1        
 | ------ dx  
 |      2    =
 | 4 + x      
 |            
/             
  
  /             
 |              
 |     1        
 | ---------- dx
 |      2       
 | /-x \        
 | |---|  + 1   
 | \ 2 /        
 |              
/               
----------------
       4        
In the integral
  /             
 |              
 |     1        
 | ---------- dx
 |      2       
 | /-x \        
 | |---|  + 1   
 | \ 2 /        
 |              
/               
----------------
       4        
do replacement
    -x 
v = ---
     2 
then
the integral =
  /                   
 |                    
 |   1                
 | ------ dv          
 |      2             
 | 1 + v              
 |                    
/              atan(v)
------------ = -------
     4            4   
do backward replacement
  /                       
 |                        
 |     1                  
 | ---------- dx          
 |      2                 
 | /-x \                  
 | |---|  + 1             
 | \ 2 /               /x\
 |                 atan|-|
/                      \2/
---------------- = -------
       4              2   
Solution is:
        /x\
    atan|-|
        \2/
C + -------
       2   
The answer (Indefinite) [src]
  /                    /x\
 |                 atan|-|
 |   1                 \2/
 | ------ dx = C + -------
 |      2             2   
 | 4 + x                  
 |                        
/                         
1x2+4dx=C+atan(x2)2\int \frac{1}{x^{2} + 4}\, dx = C + \frac{\operatorname{atan}{\left(\frac{x}{2} \right)}}{2}
The graph
0.001.000.100.200.300.400.500.600.700.800.900.000.50
The answer [src]
atan(1/2)
---------
    2    
atan(12)2\frac{\operatorname{atan}{\left(\frac{1}{2} \right)}}{2}
=
=
atan(1/2)
---------
    2    
atan(12)2\frac{\operatorname{atan}{\left(\frac{1}{2} \right)}}{2}
atan(1/2)/2
Numerical answer [src]
0.231823804500403
0.231823804500403
The graph
Integral of 1/(4+x^2) dx

    Use the examples entering the upper and lower limits of integration.