Use the fundamental identities to simplify the expression. There is more than one correct form of the answer.

7 sec^2 x (1 - sin^2 x)

The fundamental identities that are useful are

Pythagorean relations: cos^2 x + sin^2 x = 1

Inverse trigo identity: cos x = 1/secx

Applying the pythagorean theorem, the equation would be:

7sec^2 x (cos^2 x)

Then applying the inverse trigo identity, the answer would be 7.

Thus, the final answer is 7.