 Hello and welcome to the session. In this session we discussed the following question that says, simplify sine theta plus cos theta upon sine theta plus cos theta plus sine theta cos theta. Let's move on to the solution. We need to simplify sine theta plus cos theta this whole upon sine theta plus cos theta plus sine theta into cos theta. Now, we call the formula for a cube plus b cube this is equal to a plus b this whole multiplied by a square plus b square minus a b. Now, using this formula we find the value for sine cube theta plus cos cube theta. So we get this is further equal to sine theta plus cos theta this whole multiplied by sine square theta plus cos square theta minus sine theta into cos theta the whole divided by sine theta plus cos theta plus sine theta into cos theta. Now, this sine theta plus cos theta cancels with sine theta plus cos theta and so this is equal to sine square theta plus cos square theta minus sine theta into cos theta plus sine theta into cos theta sine theta cos theta and minus sine theta cos theta cancels and this is equal to sine square theta plus cos square theta which is equal to 1 since we know the identity sine square theta plus cos square theta is equal to 1. Thus, we get the given expression sine cube theta plus cos cube theta the whole upon sine theta plus cos theta plus sine theta cos theta is equal to 1. So, this is our final answer this completes the session hope you have understood the solution of this question.