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2/(9x^2+4)

Integral of 2/(9x^2+4) dx

Limits of integration:

from to
v

The graph:

from to

Piecewise:

The solution

You have entered [src]
  1            
  /            
 |             
 |     2       
 |  -------- dx
 |     2       
 |  9*x  + 4   
 |             
/              
0              
$$\int\limits_{0}^{1} \frac{2}{9 x^{2} + 4}\, dx$$
Integral(2/(9*x^2 + 4), (x, 0, 1))
Detail solution
We have the integral:
  /           
 |            
 |    2       
 | -------- dx
 |    2       
 | 9*x  + 4   
 |            
/             
Rewrite the integrand
               /2\    
               |-|    
   2           \4/    
-------- = -----------
   2             2    
9*x  + 4   /-3*x\     
           |----|  + 1
           \ 2  /     
or
  /             
 |              
 |    2         
 | -------- dx  
 |    2        =
 | 9*x  + 4     
 |              
/               
  
  /              
 |               
 |      1        
 | ----------- dx
 |       2       
 | /-3*x\        
 | |----|  + 1   
 | \ 2  /        
 |               
/                
-----------------
        2        
In the integral
  /              
 |               
 |      1        
 | ----------- dx
 |       2       
 | /-3*x\        
 | |----|  + 1   
 | \ 2  /        
 |               
/                
-----------------
        2        
do replacement
    -3*x
v = ----
     2  
then
the integral =
  /                   
 |                    
 |   1                
 | ------ dv          
 |      2             
 | 1 + v              
 |                    
/              atan(v)
------------ = -------
     2            2   
do backward replacement
  /                          
 |                           
 |      1                    
 | ----------- dx            
 |       2                   
 | /-3*x\                    
 | |----|  + 1               
 | \ 2  /               /3*x\
 |                  atan|---|
/                       \ 2 /
----------------- = ---------
        2               3    
Solution is:
        /3*x\
    atan|---|
        \ 2 /
C + ---------
        3    
The answer (Indefinite) [src]
  /                      /3*x\
 |                   atan|---|
 |    2                  \ 2 /
 | -------- dx = C + ---------
 |    2                  3    
 | 9*x  + 4                   
 |                            
/                             
$$\int \frac{2}{9 x^{2} + 4}\, dx = C + \frac{\operatorname{atan}{\left(\frac{3 x}{2} \right)}}{3}$$
The graph
The answer [src]
atan(3/2)
---------
    3    
$$\frac{\operatorname{atan}{\left(\frac{3}{2} \right)}}{3}$$
=
=
atan(3/2)
---------
    3    
$$\frac{\operatorname{atan}{\left(\frac{3}{2} \right)}}{3}$$
atan(3/2)/3
Numerical answer [src]
0.32759790774911
0.32759790774911
The graph
Integral of 2/(9x^2+4) dx

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