contestada

In the following problems, name the method by identifying whether the integral can be evaluated using substitution, integration by parts, or partial fractions.

In the following problems name the method by identifying whether the integral can be evaluated using substitution integration by parts or partial fractions class=

Respuesta :

Integration by parts or using partial fractions is overkill. Both can be done with simple substitutions.

For the first integral, take y = x + 1 and dy = dx.

[tex]\displaystyle \int \frac2{(x+1)^2} \, dx = \int \frac2{y^2} \, dy = -\frac2y + C \\\\ = -\frac2{x+1} + C[/tex]

For the second integral, use the same substitution.

[tex]\displaystyle \int \frac{x-1}{(x+1)^2} \, dx = \int \frac{(y-1)-1}{y^2} \, dy = \int \left(\frac1y - \frac2{y^2}\right) \, dy = \ln|y| + \frac2y + C \\\\ = \ln|x+1| + \frac2{x+1} + C[/tex]