CPM Homework Help : PCT Problem 11-60

Solve for $c$ : $c^{4} − 12c^{2} − 64 = 0$ .

Hint 1:

Factor.

$\left(c^2 ± ?\right)\left(c^2 ± ?\right) = 0$

Hint 2:

The original equation has $c^{4}$ , so you should be looking for $4$ solutions.