Use the fundamental identities to simplify the expression Us

Use the fundamental identities to simplify the expression. Use the table feature of a graphing utility to check your result numerically.

7 sec²x(1-sin^2 x)

Solution

7 sec²x(1-sin^2 x)

we know secx = 1/cosx

(7/cos^2x)(1- sin^2x)

we know sin^2x + cos^2x = 1

So, (7/cos^2x)(cos^2x)

7     (simplified)