Verify That Each Equation Is an Identity $\frac{\sec ^{2} x-\tan ^{2} x}{\cos ^{2} x}-1=\tan ^{2} x$

Essay

Verify that each equation is an identity.
- $\frac{\sec ^{2} x-\tan ^{2} x}{\cos ^{2} x}-1=\tan ^{2} x$