1. The problem statement, all variables and given/known data The graphs of f( ) = 2sin() - 1 (blue) , and g() = 3cos() + 2 (red) are shown below: http://img403.imageshack.us/img403/6991/38ah7.jpg [Broken] http://g.imageshack.us/g.php?h=403&i=38ah7.jpg [Broken] What equation would have the intersection points of the graph its solutions? 2. Relevant equations http://www.eformulae.com/images/trigonometry_001.gif [Broken] 3. The attempt at a solution From using a calculator (set to degrees) I discovered the intersection points of the two graphs. They are: 1: (112.61986, 0.84615385) and 2: (180, -1) Therefore, to find an equation that will have these two points in its graph I did the following: 2sin(x) - 1 = 3cos(x) + 2 which eventually came to: 2sin(x) - 3cos(x) = 3 which brought me to: 2sinxcosx - 3cosx=3 cosx (2sins - 3) = 3 so cosx = 3 or sinx=3 Needless to say, it is wrong. Can somebody tell me a strategy? Thanks in advance.