0
582views
Resolve into partial fractions $\frac{x^{2}+1}{x(x^{2}-1)}$
1 Answer
written 5.2 years ago by |
Solution:
$\frac{x^{2}+1}{x(x+1)(x-1)} = \frac{A}{x} +\frac{B}{x+1} + \frac{c}{x-1}$
$x^{2}+1 = A(x-1)(x+1)+B(x)(x-1)+C(x)(x+1)$
put x = 0
0+1 = A(0-1)(0+1)
A = -1
put x = -1
$(-1)^{2} + 1 = B(-1)(-1-1)$
B = 1
put x = 1
$1^{2} + 1 = C(1)(1+1)$
C = 1
$\frac{x^{2}+1}{x(x+1)(x-1)} = \frac{-1}{x} +\frac{1}{x+1} + \frac{1}{x-1}$