## Calculus with Applications (10th Edition)

$x^2-16\gt0$ $(x+4)(x-4)\gt0$ $x\lt-4$ and $x\gt4$
Step 1: Factorize quadratic inequality (difference of squares) Step 2: The roots of the function is $x=-4$ and $x=4$ Step 3: The quadratic function of the inequality is greater than $0$ at $x\lt-4$ and $x\gt4$