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1/sin(2*x)

Integral of 1/sin(2*x) dx

Limits of integration:

from to
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The graph:

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Piecewise:

The solution

You have entered [src]
  1            
  /            
 |             
 |     1       
 |  -------- dx
 |  sin(2*x)   
 |             
/              
0              
$$\int\limits_{0}^{1} \frac{1}{\sin{\left(2 x \right)}}\, dx$$
Integral(1/sin(2*x), (x, 0, 1))
Detail solution
We have the integral:
  /           
 |            
 |    1       
 | -------- dx
 | sin(2*x)   
 |            
/             
The integrand
   1    
--------
sin(2*x)
Multiply numerator and denominator by
sin(2*x)
we get
   1        sin(2*x)
-------- = ---------
sin(2*x)      2     
           sin (2*x)
Because
sin(a)^2 + cos(a)^2 = 1
then
   2               2     
sin (2*x) = 1 - cos (2*x)
transform the denominator
 sin(2*x)      sin(2*x)  
--------- = -------------
   2               2     
sin (2*x)   1 - cos (2*x)
do replacement
u = cos(2*x)
then the integral
  /                  
 |                   
 |    sin(2*x)       
 | ------------- dx  
 |        2         =
 | 1 - cos (2*x)     
 |                   
/                    
  
  /                  
 |                   
 |    sin(2*x)       
 | ------------- dx  
 |        2         =
 | 1 - cos (2*x)     
 |                   
/                    
  
Because du = -2*dx*sin(2*x)
  /             
 |              
 |    -1        
 | ---------- du
 |   /     2\   
 | 2*\1 - u /   
 |              
/               
Rewrite the integrand
   -1        -1  /  1       1  \
---------- = ---*|----- + -----|
  /     2\   2*2 \1 - u   1 + u/
2*\1 - u /                      
then
                       /             /          
                      |             |           
                      |   1         |   1       
                      | ----- du    | ----- du  
  /                   | 1 + u       | 1 - u     
 |                    |             |           
 |    -1             /             /           =
 | ---------- du = - ----------- - -----------  
 |   /     2\             4             4       
 | 2*\1 - u /                                   
 |                                              
/                                               
  
= -log(1 + u)/4 + log(-1 + u)/4
do backward replacement
u = cos(2*x)
The answer
  /                                                           
 |                                                            
 |    1            log(1 + cos(2*x))   log(-1 + cos(2*x))     
 | -------- dx = - ----------------- + ------------------ + C0
 | sin(2*x)                4                   4              
 |                                                            
/                                                             
where C0 is constant, independent of x
The answer (Indefinite) [src]
  /                                                        
 |                                                         
 |    1              log(1 + cos(2*x))   log(-1 + cos(2*x))
 | -------- dx = C - ----------------- + ------------------
 | sin(2*x)                  4                   4         
 |                                                         
/                                                          
$$\int \frac{1}{\sin{\left(2 x \right)}}\, dx = C + \frac{\log{\left(\cos{\left(2 x \right)} - 1 \right)}}{4} - \frac{\log{\left(\cos{\left(2 x \right)} + 1 \right)}}{4}$$
The graph
The answer [src]
     pi*I
oo + ----
      4  
$$\infty + \frac{i \pi}{4}$$
=
=
     pi*I
oo + ----
      4  
$$\infty + \frac{i \pi}{4}$$
oo + pi*i/4
Numerical answer [src]
22.2667344290549
22.2667344290549
The graph
Integral of 1/sin(2*x) dx

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