Mister Exam

Other calculators


(x+1)/(x^2-4)

Integral of (x+1)/(x^2-4) dx

Limits of integration:

from to
v

The graph:

from to

Piecewise:

The solution

You have entered [src]
  1          
  /          
 |           
 |  x + 1    
 |  ------ dx
 |   2       
 |  x  - 4   
 |           
/            
0            
01x+1x24dx\int\limits_{0}^{1} \frac{x + 1}{x^{2} - 4}\, dx
Integral((x + 1)/(x^2 - 1*4), (x, 0, 1))
Detail solution
  1. There are multiple ways to do this integral.

    Method #1

    1. Rewrite the integrand:

      x+1x24=14(x+2)+34(x2)\frac{x + 1}{x^{2} - 4} = \frac{1}{4 \left(x + 2\right)} + \frac{3}{4 \left(x - 2\right)}

    2. Integrate term-by-term:

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

        14(x+2)dx=1x+2dx4\int \frac{1}{4 \left(x + 2\right)}\, dx = \frac{\int \frac{1}{x + 2}\, dx}{4}

        1. Let u=x+2u = x + 2.

          Then let du=dxdu = dx and substitute dudu:

          1udu\int \frac{1}{u}\, du

          1. The integral of 1u\frac{1}{u} is log(u)\log{\left(u \right)}.

          Now substitute uu back in:

          log(x+2)\log{\left(x + 2 \right)}

        So, the result is: log(x+2)4\frac{\log{\left(x + 2 \right)}}{4}

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

        34(x2)dx=31x2dx4\int \frac{3}{4 \left(x - 2\right)}\, dx = \frac{3 \int \frac{1}{x - 2}\, dx}{4}

        1. Let u=x2u = x - 2.

          Then let du=dxdu = dx and substitute dudu:

          1udu\int \frac{1}{u}\, du

          1. The integral of 1u\frac{1}{u} is log(u)\log{\left(u \right)}.

          Now substitute uu back in:

          log(x2)\log{\left(x - 2 \right)}

        So, the result is: 3log(x2)4\frac{3 \log{\left(x - 2 \right)}}{4}

      The result is: 3log(x2)4+log(x+2)4\frac{3 \log{\left(x - 2 \right)}}{4} + \frac{\log{\left(x + 2 \right)}}{4}

    Method #2

    1. Rewrite the integrand:

      x+1x24=xx24+1x24\frac{x + 1}{x^{2} - 4} = \frac{x}{x^{2} - 4} + \frac{1}{x^{2} - 4}

    2. Integrate term-by-term:

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

        xx24dx=2xx24dx2\int \frac{x}{x^{2} - 4}\, dx = \frac{\int \frac{2 x}{x^{2} - 4}\, dx}{2}

        1. Let u=x24u = x^{2} - 4.

          Then let du=2xdxdu = 2 x dx and substitute du2\frac{du}{2}:

          12udu\int \frac{1}{2 u}\, du

          1. The integral of 1u\frac{1}{u} is log(u)\log{\left(u \right)}.

          Now substitute uu back in:

          log(x24)\log{\left(x^{2} - 4 \right)}

        So, the result is: log(x24)2\frac{\log{\left(x^{2} - 4 \right)}}{2}

      1. Rewrite the integrand:

        1x24=1x+2+1x24\frac{1}{x^{2} - 4} = \frac{- \frac{1}{x + 2} + \frac{1}{x - 2}}{4}

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

        1x+2+1x24dx=(1x+2+1x2)dx4\int \frac{- \frac{1}{x + 2} + \frac{1}{x - 2}}{4}\, dx = \frac{\int \left(- \frac{1}{x + 2} + \frac{1}{x - 2}\right)\, dx}{4}

        1. Integrate term-by-term:

          1. The integral of 1x2\frac{1}{x - 2} is log(x2)\log{\left(x - 2 \right)}.

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

            (1x+2)dx=1x+2dx\int \left(- \frac{1}{x + 2}\right)\, dx = - \int \frac{1}{x + 2}\, dx

            1. The integral of 1x+2\frac{1}{x + 2} is log(x+2)\log{\left(x + 2 \right)}.

            So, the result is: log(x+2)- \log{\left(x + 2 \right)}

          The result is: log(x2)log(x+2)\log{\left(x - 2 \right)} - \log{\left(x + 2 \right)}

        So, the result is: log(x2)4log(x+2)4\frac{\log{\left(x - 2 \right)}}{4} - \frac{\log{\left(x + 2 \right)}}{4}

      The result is: log(x2)4log(x+2)4+log(x24)2\frac{\log{\left(x - 2 \right)}}{4} - \frac{\log{\left(x + 2 \right)}}{4} + \frac{\log{\left(x^{2} - 4 \right)}}{2}

  2. Add the constant of integration:

    3log(x2)4+log(x+2)4+constant\frac{3 \log{\left(x - 2 \right)}}{4} + \frac{\log{\left(x + 2 \right)}}{4}+ \mathrm{constant}


The answer is:

3log(x2)4+log(x+2)4+constant\frac{3 \log{\left(x - 2 \right)}}{4} + \frac{\log{\left(x + 2 \right)}}{4}+ \mathrm{constant}

The answer (Indefinite) [src]
  /                                          
 |                                           
 | x + 1           log(2 + x)   3*log(-2 + x)
 | ------ dx = C + ---------- + -------------
 |  2                  4              4      
 | x  - 4                                    
 |                                           
/                                            
log(x+2)4+3log(x2)4{{\log \left(x+2\right)}\over{4}}+{{3\,\log \left(x-2\right)}\over{ 4}}
The graph
0.001.000.100.200.300.400.500.600.700.800.90-1.00.0
The answer [src]
          log(3)
-log(2) + ------
            4   
log34log2{{\log 3}\over{4}}-\log 2
=
=
          log(3)
-log(2) + ------
            4   
log(2)+log(3)4- \log{\left(2 \right)} + \frac{\log{\left(3 \right)}}{4}
Numerical answer [src]
-0.418494108392918
-0.418494108392918
The graph
Integral of (x+1)/(x^2-4) dx

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