I know the formula that I have to show is true. However, I am confused where to start to prove it. I thought multiplying the 2 matrices together but that’s not possible. Can someone start me off please?
Have to use letters. $p$ and $q$ have to represent ANY element of $P$. If you use examples you can show it, sure, but all that means is that the proof holds for those examples. It means nothing for the entire group.
Also, use the function symbol given to you so you avoid confusing the grader, if there is one. $\varphi$