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1/(81x^2+16)

Integral of 1/(81x^2+16) dx

Limits of integration:

from to
v

The graph:

from to

Piecewise:

The solution

You have entered [src]
  1                
  /                
 |                 
 |        1        
 |  1*---------- dx
 |        2        
 |    81*x  + 16   
 |                 
/                  
0                  
$$\int\limits_{0}^{1} 1 \cdot \frac{1}{81 x^{2} + 16}\, dx$$
Integral(1/(81*x^2 + 16), (x, 0, 1))
Detail solution
We have the integral:
  /                 
 |                  
 |         1        
 | 1*1*---------- dx
 |         2        
 |     81*x  + 16   
 |                  
/                   
Rewrite the integrand
      1                  1          
1*---------- = ---------------------
      2           /           2    \
  81*x  + 16      |/  9*x    \     |
               16*||- --- + 0|  + 1|
                  \\   4     /     /
or
  /                   
 |                    
 |         1          
 | 1*1*---------- dx  
 |         2         =
 |     81*x  + 16     
 |                    
/                     
  
  /                   
 |                    
 |        1           
 | ---------------- dx
 |            2       
 | /  9*x    \        
 | |- --- + 0|  + 1   
 | \   4     /        
 |                    
/                     
----------------------
          16          
In the integral
  /                   
 |                    
 |        1           
 | ---------------- dx
 |            2       
 | /  9*x    \        
 | |- --- + 0|  + 1   
 | \   4     /        
 |                    
/                     
----------------------
          16          
do replacement
    -9*x
v = ----
     4  
then
the integral =
  /                   
 |                    
 |   1                
 | ------ dv          
 |      2             
 | 1 + v              
 |                    
/              atan(v)
------------ = -------
     16           16  
do backward replacement
  /                               
 |                                
 |        1                       
 | ---------------- dx            
 |            2                   
 | /  9*x    \                    
 | |- --- + 0|  + 1               
 | \   4     /               /9*x\
 |                       atan|---|
/                            \ 4 /
---------------------- = ---------
          16                 36   
Solution is:
        /9*x\
    atan|---|
        \ 4 /
C + ---------
        36   
The answer (Indefinite) [src]
  /                          /9*x\
 |                       atan|---|
 |       1                   \ 4 /
 | 1*---------- dx = C + ---------
 |       2                   36   
 |   81*x  + 16                   
 |                                
/                                 
$${{\arctan \left({{9\,x}\over{4}}\right)}\over{36}}$$
The graph
The answer [src]
atan(9/4)
---------
    36   
$${{\arctan \left({{9}\over{4}}\right)}\over{36}}$$
=
=
atan(9/4)
---------
    36   
$$\frac{\operatorname{atan}{\left(\frac{9}{4} \right)}}{36}$$
Numerical answer [src]
0.0320158888115463
0.0320158888115463
The graph
Integral of 1/(81x^2+16) dx

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