Given Tan & # 178; a = 2tan & # 178; B + 1, then cos2a + Sin & # 178; b =? The finer the process, the better

Given Tan & # 178; a = 2tan & # 178; B + 1, then cos2a + Sin & # 178; b =? The finer the process, the better

We can get Tan and\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\/ (2sec & # 178; b) - 1 / sec & # 17