Answer
$\frac{1}{c^2 -1}$
Work Step by Step
To find the reciprocal of $c^2 - 1$, we must first write it as a fraction: $\frac{c^2-1}{1}$. Nowwe need to find that value that multiplies by the expression to equal 1, which is $\frac{1}{c^2 -1}$.
$\frac{c^2-1}{1} \times \frac{1}{c^2 -1} = 1$
