Integral of 2cos4x dx

The solution

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  pi              
  --              
  2               
   /              
  |               
  |  2*cos(4*x) dx
  |               
 /                
-pi               
----              
 2

$$\int\limits_{- \frac{\pi}{2}}^{\frac{\pi}{2}} 2 \cos{\left(4 x \right)}\, dx$$

Integral(2*cos(4*x), (x, -pi/2, pi/2))

Detail solution

The integral of a constant times a function is the constant times the integral of the function:

$\int 2 \cos{\left(4 x \right)}\, dx = 2 \int \cos{\left(4 x \right)}\, dx$
1. Let $u = 4 x$ .
  
  Then let $du = 4 dx$ and substitute $\frac{du}{4}$ :
  
  $\int \frac{\cos{\left(u \right)}}{4}\, du$
  1. The integral of a constant times a function is the constant times the integral of the function:
    
    $\int \cos{\left(u \right)}\, du = \frac{\int \cos{\left(u \right)}\, du}{4}$
    1. The integral of cosine is sine:
      
      $\int \cos{\left(u \right)}\, du = \sin{\left(u \right)}$
    So, the result is: $\frac{\sin{\left(u \right)}}{4}$
  Now substitute $u$ back in:
  
  $\frac{\sin{\left(4 x \right)}}{4}$
So, the result is: $\frac{\sin{\left(4 x \right)}}{2}$
Add the constant of integration:

$\frac{\sin{\left(4 x \right)}}{2}+ \mathrm{constant}$

The answer is:

$\frac{\sin{\left(4 x \right)}}{2}+ \mathrm{constant}$

The answer (Indefinite) [src]

  /                            
 |                     sin(4*x)
 | 2*cos(4*x) dx = C + --------
 |                        2    
/

$$\int 2 \cos{\left(4 x \right)}\, dx = C + \frac{\sin{\left(4 x \right)}}{2}$$

Simplify

The graph

Plot the graph f(x)

The answer [src]

$$0$$

Numerical answer [src]

-2.45395937220138e-16

-2.45395937220138e-16

The graph

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

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Integral of 2cos4x dx

Limits of integration:

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Piecewise:

The solution