How do you prove # [(1)/(1-sinx)]+[(1)/(1+sinx)]=2sec^2x#?
The formula can be proven by applying: 1) Least common multiple; 2) applying the trigonometric entity
Key-concept: Least common multiple; when no common multiples, just multiply the terms in the denominator.
The above formula can be proven by transforming left side to right side:
To arrive to right-hand side, just divide the denominator to
By simple algebra and make use of
To finish, remember that