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1/(1+4x^2)

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

Limits of integration:

from to
v

The graph:

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Piecewise:

The solution

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  1              
  /              
 |               
 |       1       
 |  1*-------- dx
 |           2   
 |    1 + 4*x    
 |               
/                
0                
$$\int\limits_{0}^{1} 1 \cdot \frac{1}{4 x^{2} + 1}\, dx$$
Integral(1/(1 + 4*x^2), (x, 0, 1))
Detail solution
We have the integral:
  /               
 |                
 |        1       
 | 1*1*-------- dx
 |            2   
 |     1 + 4*x    
 |                
/                 
Rewrite the integrand
     1                1         
1*-------- = -------------------
         2     /          2    \
  1 + 4*x    1*\(-2*x + 0)  + 1/
or
  /                 
 |                  
 |        1         
 | 1*1*-------- dx  
 |            2    =
 |     1 + 4*x      
 |                  
/                   
  
  /                  
 |                   
 |        1          
 | --------------- dx
 |           2       
 | (-2*x + 0)  + 1   
 |                   
/                    
In the integral
  /                  
 |                   
 |        1          
 | --------------- dx
 |           2       
 | (-2*x + 0)  + 1   
 |                   
/                    
do replacement
v = -2*x
then
the integral =
  /                   
 |                    
 |   1                
 | ------ dv = atan(v)
 |      2             
 | 1 + v              
 |                    
/                     
do backward replacement
  /                              
 |                               
 |        1             atan(2*x)
 | --------------- dx = ---------
 |           2              2    
 | (-2*x + 0)  + 1               
 |                               
/                                
Solution is:
    atan(2*x)
C + ---------
        2    
The answer (Indefinite) [src]
  /                             
 |                              
 |      1              atan(2*x)
 | 1*-------- dx = C + ---------
 |          2              2    
 |   1 + 4*x                    
 |                              
/                               
$${{\arctan \left(2\,x\right)}\over{2}}$$
The graph
The answer [src]
atan(2)
-------
   2   
$${{\arctan 2}\over{2}}$$
=
=
atan(2)
-------
   2   
$$\frac{\operatorname{atan}{\left(2 \right)}}{2}$$
Numerical answer [src]
0.553574358897045
0.553574358897045
The graph
Integral of 1/(1+4x^2) dx

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