 Hello friends welcome to the session I am Alka we are going to discuss matrices. We have to simplify cos theta matrix cos theta sin theta minus sin theta cos theta plus sin theta into matrix sin theta minus cos theta cos theta sin theta. Now let's start with the solution. Now we will multiply cos theta with the given matrix this will give us cos square theta cos theta sin theta then minus cos theta sin theta and cos square theta plus on multiplying sin theta with the given matrix we get sin square theta minus sin theta cos theta sin theta cos theta and sin square theta. This is equal to cos square theta plus sin square theta cos theta sin theta minus sin theta cos theta and then minus cos theta sin theta plus sin theta cos theta minus cos square theta plus sin square theta and we all know that cos square theta plus sin square theta equal to 1 we get 1 0 0 1 matrix therefore 1 0 0 1 is the required answer hope you understood the solution and enjoyed the session goodbye and take care.