Mister Exam

Integral of sin3x/3 dx

Limits of integration:

from to
v

The graph:

from to

Piecewise:

The solution

You have entered [src]
  t            
  /            
 |             
 |  sin(3*x)   
 |  -------- dx
 |     3       
 |             
/              
0              
0tsin(3x)3dx\int\limits_{0}^{t} \frac{\sin{\left(3 x \right)}}{3}\, dx
Detail solution
  1. The integral of a constant times a function is the constant times the integral of the function:

    sin(3x)3dx=sin(3x)dx3\int \frac{\sin{\left(3 x \right)}}{3}\, dx = \frac{\int \sin{\left(3 x \right)}\, dx}{3}

    1. Let u=3xu = 3 x.

      Then let du=3dxdu = 3 dx and substitute du3\frac{du}{3}:

      sin(u)9du\int \frac{\sin{\left(u \right)}}{9}\, du

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

        sin(u)3du=sin(u)du3\int \frac{\sin{\left(u \right)}}{3}\, du = \frac{\int \sin{\left(u \right)}\, du}{3}

        1. The integral of sine is negative cosine:

          sin(u)du=cos(u)\int \sin{\left(u \right)}\, du = - \cos{\left(u \right)}

        So, the result is: cos(u)3- \frac{\cos{\left(u \right)}}{3}

      Now substitute uu back in:

      cos(3x)3- \frac{\cos{\left(3 x \right)}}{3}

    So, the result is: cos(3x)9- \frac{\cos{\left(3 x \right)}}{9}

  2. Add the constant of integration:

    cos(3x)9+constant- \frac{\cos{\left(3 x \right)}}{9}+ \mathrm{constant}


The answer is:

cos(3x)9+constant- \frac{\cos{\left(3 x \right)}}{9}+ \mathrm{constant}

The answer (Indefinite) [src]
  /                          
 |                           
 | sin(3*x)          cos(3*x)
 | -------- dx = C - --------
 |    3                 9    
 |                           
/                            
cos(3x)9-{{\cos \left(3\,x\right)}\over{9}}
The answer [src]
1   cos(3*t)
- - --------
9      9    
cos(3t)9+19- \frac{\cos{\left(3 t \right)}}{9} + \frac{1}{9}
=
=
1   cos(3*t)
- - --------
9      9    
cos(3t)9+19- \frac{\cos{\left(3 t \right)}}{9} + \frac{1}{9}

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