Question:

Integrate the rational function: \(\frac{2x-3}{(x^2-1)(2x+3)}\)

Updated On: Oct 4, 2023
Hide Solution
collegedunia
Verified By Collegedunia

Solution and Explanation

\(\frac{2x-3}{(x^2-1)(2x+3)}\)\(\frac{2x-3}{(x+1)(x-1)(2x+3)}\)

Let \(\frac{2x-3}{(x+1)(x-1)(2x+3)}= \frac{A}{(x+1)}\frac{B}{(x-1)}+\frac{C}{(2x+3)}\)

\(\Rightarrow\) (2x-3) = A(x-1)(2x+3)+B(x+1)(2x+3)+C(x+1)(x-1)

\(\Rightarrow\) (2x-3) = A(2x2+x-3)+B(2x2+5x+3)+C(x2-1)

\(\Rightarrow\) (2x-3) = A(2A+2B+C)x2+(A+5B)x+(-3A+3B-C)

Equating the coefficients of x2 and x, we obtain

B = -\(\frac{1}{10}\), A = \(\frac{5}{2}\), and C = -\(\frac{24}{5}\)

∴ \(\frac{2x-3}{(x+1)(x-1)(2x+3)}= \frac{5}{2(x+1)}\frac{1}{10(x-1)}+\frac{24}{5(2x+3)}\)

\(\Rightarrow\int\frac{2x-3}{(x+1)(x-1)(2x+3)}dx= \frac{5}{2}\int\frac{1}{(x+1)}dx-\frac{1}{10}\int\frac{1}{x-1}dx-\frac{24}{5}\int\frac{1}{(2x+3)}dx\)

\(\frac{5}{2}\log\mid x+1\mid-\frac{1}{10}\log \mid x-1\mid-\frac{24}{5*2}\log\mid 2x+3\mid\)

=\(\frac{5}{2}\log\mid x+1\mid-\frac{1}{10}\log\mid x-1\mid-\frac{12}{5}\log\mid 2x+3 \mid+C\)

Was this answer helpful?
0
0

Concepts Used:

Integration by Partial Fractions

The number of formulas used to decompose the given improper rational functions is given below. By using the given expressions, we can quickly write the integrand as a sum of proper rational functions.

For examples,