Accedmychevron_right11thchevron_rightmathchevron_rightPartial Fractionschevron_rightExercise 5.1

Solution

x2+1(x+1)(x1)\frac{x^2+1}{(x+1)(x-1)}

First make it a mixed form:

x2+1x21=1+2x21\frac{x^2+1}{x^2-1}=1+\frac{2}{x^2-1}

Now:

2x21=1x11x+1\frac{2}{x^2-1}=\frac{1}{x-1}-\frac{1}{x+1}

Hence:

x2+1(x+1)(x1)=1+1x11x+1\boxed{\frac{x^2+1}{(x+1)(x-1)}=1+\frac{1}{x-1}-\frac{1}{x+1}}