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Identical expressions
(3x+ one)÷((x+ one)×(x^ two + one))
(3x plus 1)÷((x plus 1)×(x squared plus 1))
(3x plus one)÷((x plus one)×(x to the power of two plus one))
(3x+1)÷((x+1)×(x2+1))
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(3x+1)÷((x+1)×(x²+1))
(3x+1)÷((x+1)×(x to the power of 2+1))
3x+1÷x+1×x^2+1
(3x+1)÷((x+1)×(x^2+1))dx
Similar expressions
(3x+1)÷((x+1)×(x^2-1))
(3x-1)÷((x+1)×(x^2+1))
(3x+1)÷((x-1)×(x^2+1))

Solving integrals/ (3x+1)÷((x+1)×(x^2+1))

Integral of (3x+1)÷((x+1)×(x^2+1)) dx

The solution

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  1                    
  /                    
 |                     
 |      3*x + 1        
 |  ---------------- dx
 |          / 2    \   
 |  (x + 1)*\x  + 1/   
 |                     
/                      
0

$$\int\limits_{0}^{1} \frac{3 x + 1}{\left(x + 1\right) \left(x^{2} + 1\right)}\, dx$$

Integral((3*x + 1)/(((x + 1)*(x^2 + 1))), (x, 0, 1))

Detail solution

There are multiple ways to do this integral.
Method #1
1. Rewrite the integrand:
  
  $\frac{3 x + 1}{\left(x + 1\right) \left(x^{2} + 1\right)} = \frac{x + 2}{x^{2} + 1} - \frac{1}{x + 1}$
2. Integrate term-by-term:
  1. Rewrite the integrand:
    
    $\frac{x + 2}{x^{2} + 1} = \frac{x}{x^{2} + 1} + \frac{2}{x^{2} + 1}$
  2. Integrate term-by-term:
    1. The integral of a constant times a function is the constant times the integral of the function:
      
      $\int \frac{x}{x^{2} + 1}\, dx = \frac{\int \frac{2 x}{x^{2} + 1}\, dx}{2}$
      
      Let $u = x^{2} + 1$ .
      
      Then let $du = 2 x dx$ and substitute $\frac{du}{2}$ :
      
      $\int \frac{1}{2 u}\, du$
      
      The integral of $\frac{1}{u}$ is $\log{\left(u \right)}$ .
      
      Now substitute $u$ back in:
      
      $\log{\left(x^{2} + 1 \right)}$
      
      So, the result is: $\frac{\log{\left(x^{2} + 1 \right)}}{2}$
    1. The integral of a constant times a function is the constant times the integral of the function:
      
      $\int \frac{2}{x^{2} + 1}\, dx = 2 \int \frac{1}{x^{2} + 1}\, dx$
      
      The integral of $\frac{1}{x^{2} + 1}$ is $\operatorname{atan}{\left(x \right)}$ .
      
      So, the result is: $2 \operatorname{atan}{\left(x \right)}$
    The result is: $\frac{\log{\left(x^{2} + 1 \right)}}{2} + 2 \operatorname{atan}{\left(x \right)}$
  1. The integral of a constant times a function is the constant times the integral of the function:
    
    $\int \left(- \frac{1}{x + 1}\right)\, dx = - \int \frac{1}{x + 1}\, dx$
    1. Let $u = x + 1$ .
      
      Then let $du = dx$ and substitute $du$ :
      
      $\int \frac{1}{u}\, du$
      
      The integral of $\frac{1}{u}$ is $\log{\left(u \right)}$ .
      
      Now substitute $u$ back in:
      
      $\log{\left(x + 1 \right)}$
    So, the result is: $- \log{\left(x + 1 \right)}$
  The result is: $- \log{\left(x + 1 \right)} + \frac{\log{\left(x^{2} + 1 \right)}}{2} + 2 \operatorname{atan}{\left(x \right)}$
Method #2
1. Rewrite the integrand:
  
  $\frac{3 x + 1}{\left(x + 1\right) \left(x^{2} + 1\right)} = \frac{3 x + 1}{x^{3} + x^{2} + x + 1}$
2. Rewrite the integrand:
  
  $\frac{3 x + 1}{x^{3} + x^{2} + x + 1} = \frac{x + 2}{x^{2} + 1} - \frac{1}{x + 1}$
3. Integrate term-by-term:
  1. Rewrite the integrand:
    
    $\frac{x + 2}{x^{2} + 1} = \frac{x}{x^{2} + 1} + \frac{2}{x^{2} + 1}$
  2. Integrate term-by-term:
    1. The integral of a constant times a function is the constant times the integral of the function:
      
      $\int \frac{x}{x^{2} + 1}\, dx = \frac{\int \frac{2 x}{x^{2} + 1}\, dx}{2}$
      
      Let $u = x^{2} + 1$ .
      
      Then let $du = 2 x dx$ and substitute $\frac{du}{2}$ :
      
      $\int \frac{1}{2 u}\, du$
      
      The integral of $\frac{1}{u}$ is $\log{\left(u \right)}$ .
      
      Now substitute $u$ back in:
      
      $\log{\left(x^{2} + 1 \right)}$
      
      So, the result is: $\frac{\log{\left(x^{2} + 1 \right)}}{2}$
    1. The integral of a constant times a function is the constant times the integral of the function:
      
      $\int \frac{2}{x^{2} + 1}\, dx = 2 \int \frac{1}{x^{2} + 1}\, dx$
      
      The integral of $\frac{1}{x^{2} + 1}$ is $\operatorname{atan}{\left(x \right)}$ .
      
      So, the result is: $2 \operatorname{atan}{\left(x \right)}$
    The result is: $\frac{\log{\left(x^{2} + 1 \right)}}{2} + 2 \operatorname{atan}{\left(x \right)}$
  1. The integral of a constant times a function is the constant times the integral of the function:
    
    $\int \left(- \frac{1}{x + 1}\right)\, dx = - \int \frac{1}{x + 1}\, dx$
    1. Let $u = x + 1$ .
      
      Then let $du = dx$ and substitute $du$ :
      
      $\int \frac{1}{u}\, du$
      
      The integral of $\frac{1}{u}$ is $\log{\left(u \right)}$ .
      
      Now substitute $u$ back in:
      
      $\log{\left(x + 1 \right)}$
    So, the result is: $- \log{\left(x + 1 \right)}$
  The result is: $- \log{\left(x + 1 \right)} + \frac{\log{\left(x^{2} + 1 \right)}}{2} + 2 \operatorname{atan}{\left(x \right)}$
Method #3
1. Rewrite the integrand:
  
  $\frac{3 x + 1}{\left(x + 1\right) \left(x^{2} + 1\right)} = \frac{3 x}{x^{3} + x^{2} + x + 1} + \frac{1}{x^{3} + x^{2} + x + 1}$
2. Integrate term-by-term:
  1. The integral of a constant times a function is the constant times the integral of the function:
    
    $\int \frac{3 x}{x^{3} + x^{2} + x + 1}\, dx = 3 \int \frac{x}{x^{3} + x^{2} + x + 1}\, dx$
    1. Rewrite the integrand:
      
      $\frac{x}{x^{3} + x^{2} + x + 1} = \frac{x + 1}{2 \left(x^{2} + 1\right)} - \frac{1}{2 \left(x + 1\right)}$
    2. Integrate term-by-term:
      
      The integral of a constant times a function is the constant times the integral of the function:
      
      $\int \frac{x + 1}{2 \left(x^{2} + 1\right)}\, dx = \frac{\int \frac{x + 1}{x^{2} + 1}\, dx}{2}$
      
      Rewrite the integrand:
      
      $\frac{x + 1}{x^{2} + 1} = \frac{x}{x^{2} + 1} + \frac{1}{x^{2} + 1}$
      
      Integrate term-by-term:
      
      The integral of a constant times a function is the constant times the integral of the function:
      
      $\int \frac{x}{x^{2} + 1}\, dx = \frac{\int \frac{2 x}{x^{2} + 1}\, dx}{2}$
      
      Let $u = x^{2} + 1$ .
      
      Then let $du = 2 x dx$ and substitute $\frac{du}{2}$ :
      
      $\int \frac{1}{2 u}\, du$
      
      The integral of $\frac{1}{u}$ is $\log{\left(u \right)}$ .
      
      Now substitute $u$ back in:
      
      $\log{\left(x^{2} + 1 \right)}$
      
      So, the result is: $\frac{\log{\left(x^{2} + 1 \right)}}{2}$
      
      The integral of $\frac{1}{x^{2} + 1}$ is $\operatorname{atan}{\left(x \right)}$ .
      
      The result is: $\frac{\log{\left(x^{2} + 1 \right)}}{2} + \operatorname{atan}{\left(x \right)}$
      
      So, the result is: $\frac{\log{\left(x^{2} + 1 \right)}}{4} + \frac{\operatorname{atan}{\left(x \right)}}{2}$
      
      The integral of a constant times a function is the constant times the integral of the function:
      
      $\int \left(- \frac{1}{2 \left(x + 1\right)}\right)\, dx = - \frac{\int \frac{1}{x + 1}\, dx}{2}$
      
      Let $u = x + 1$ .
      
      Then let $du = dx$ and substitute $du$ :
      
      $\int \frac{1}{u}\, du$
      
      The integral of $\frac{1}{u}$ is $\log{\left(u \right)}$ .
      
      Now substitute $u$ back in:
      
      $\log{\left(x + 1 \right)}$
      
      So, the result is: $- \frac{\log{\left(x + 1 \right)}}{2}$
      
      The result is: $- \frac{\log{\left(x + 1 \right)}}{2} + \frac{\log{\left(x^{2} + 1 \right)}}{4} + \frac{\operatorname{atan}{\left(x \right)}}{2}$
    So, the result is: $- \frac{3 \log{\left(x + 1 \right)}}{2} + \frac{3 \log{\left(x^{2} + 1 \right)}}{4} + \frac{3 \operatorname{atan}{\left(x \right)}}{2}$
  1. Rewrite the integrand:
    
    $\frac{1}{x^{3} + x^{2} + x + 1} = - \frac{x - 1}{2 \left(x^{2} + 1\right)} + \frac{1}{2 \left(x + 1\right)}$
  2. Integrate term-by-term:
    1. The integral of a constant times a function is the constant times the integral of the function:
      
      $\int \left(- \frac{x - 1}{2 \left(x^{2} + 1\right)}\right)\, dx = - \frac{\int \frac{x - 1}{x^{2} + 1}\, dx}{2}$
      
      Rewrite the integrand:
      
      $\frac{x - 1}{x^{2} + 1} = \frac{x}{x^{2} + 1} - \frac{1}{x^{2} + 1}$
      
      Integrate term-by-term:
      
      The integral of a constant times a function is the constant times the integral of the function:
      
      $\int \frac{x}{x^{2} + 1}\, dx = \frac{\int \frac{2 x}{x^{2} + 1}\, dx}{2}$
      
      Let $u = x^{2} + 1$ .
      
      Then let $du = 2 x dx$ and substitute $\frac{du}{2}$ :
      
      $\int \frac{1}{2 u}\, du$
      
      The integral of $\frac{1}{u}$ is $\log{\left(u \right)}$ .
      
      Now substitute $u$ back in:
      
      $\log{\left(x^{2} + 1 \right)}$
      
      So, the result is: $\frac{\log{\left(x^{2} + 1 \right)}}{2}$
      
      The integral of a constant times a function is the constant times the integral of the function:
      
      $\int \left(- \frac{1}{x^{2} + 1}\right)\, dx = - \int \frac{1}{x^{2} + 1}\, dx$
      
      The integral of $\frac{1}{x^{2} + 1}$ is $\operatorname{atan}{\left(x \right)}$ .
      
      So, the result is: $- \operatorname{atan}{\left(x \right)}$
      
      The result is: $\frac{\log{\left(x^{2} + 1 \right)}}{2} - \operatorname{atan}{\left(x \right)}$
      
      So, the result is: $- \frac{\log{\left(x^{2} + 1 \right)}}{4} + \frac{\operatorname{atan}{\left(x \right)}}{2}$
    1. The integral of a constant times a function is the constant times the integral of the function:
      
      $\int \frac{1}{2 \left(x + 1\right)}\, dx = \frac{\int \frac{1}{x + 1}\, dx}{2}$
      
      Let $u = x + 1$ .
      
      Then let $du = dx$ and substitute $du$ :
      
      $\int \frac{1}{u}\, du$
      
      The integral of $\frac{1}{u}$ is $\log{\left(u \right)}$ .
      
      Now substitute $u$ back in:
      
      $\log{\left(x + 1 \right)}$
      
      So, the result is: $\frac{\log{\left(x + 1 \right)}}{2}$
    The result is: $\frac{\log{\left(x + 1 \right)}}{2} - \frac{\log{\left(x^{2} + 1 \right)}}{4} + \frac{\operatorname{atan}{\left(x \right)}}{2}$
  The result is: $- \log{\left(x + 1 \right)} + \frac{\log{\left(x^{2} + 1 \right)}}{2} + 2 \operatorname{atan}{\left(x \right)}$
Add the constant of integration:

$- \log{\left(x + 1 \right)} + \frac{\log{\left(x^{2} + 1 \right)}}{2} + 2 \operatorname{atan}{\left(x \right)}+ \mathrm{constant}$

The answer is:

$- \log{\left(x + 1 \right)} + \frac{\log{\left(x^{2} + 1 \right)}}{2} + 2 \operatorname{atan}{\left(x \right)}+ \mathrm{constant}$

The answer (Indefinite) [src]

  /                                                              
 |                              /     2\                         
 |     3*x + 1               log\1 + x /                         
 | ---------------- dx = C + ----------- - log(1 + x) + 2*atan(x)
 |         / 2    \               2                              
 | (x + 1)*\x  + 1/                                              
 |                                                               
/

$${{\log \left(x^2+1\right)}\over{2}}-\log \left(x+1\right)+2\, \arctan x$$

Simplify

The graph

Plot the graph f(x)

The answer [src]

pi   log(2)
-- - ------
2      2

$${{\pi}\over{2}}-{{\log 2}\over{2}}$$

pi   log(2)
-- - ------
2      2

$$- \frac{\log{\left(2 \right)}}{2} + \frac{\pi}{2}$$

Упростить

Numerical answer [src]

1.22422273651492

1.22422273651492

The graph

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

Other calculators

How to use it?

Identical expressions

Similar expressions

Integral of (3x+1)÷((x+1)×(x^2+1)) dx

Limits of integration:

The graph:

Piecewise:

The solution

Method #1

Method #2

Method #3