(13) (Bonus Task, 5 points) Matrix chain ending with a scalar: For X > Y > E", the chain rule is at? = Z E 814,, - 2 3%,; 3X3, Assume E\" = Y) where Y = AX + B, derive the derivative of % Hint: Firstly, it has 31's: _ 32,, AksXsl _ aAIciXE _ _ 1' = Aha, aX,,- 5m,- aX,_.,- J where 613' = 1 for E = j; otherwise, 53;,- = . Secondly, we have Be A a _A-- _A3', Lastly, you can derive the form ofa aX'