cos^2 - sin^2 / cos^2 + sin * cos = 1-tan * 1-cos / cos
There is no 1 - tan(x) on the left hand side. How can we help you if you continually post incomplete, ambiguous and wrong information, even after being asked for clarification.
If you cannot post your questions accurately people are simply not going to waste their time playing guessing games as to what the question is.
Learn some simple latex if you want your mathematical expressions to be undertsood. There is an entire forum at MHF devoted to it.