In Part A, you are asked to write a brief summary on the topic of Matrix Calculus after you have accessed and read the following references:

* Matrix Calculus: The Mathematics of 'Learning',

https://impartiallyderivative.com/2018/02/09/matrix-calculus-the-mathematics-of- learning/

* Calculus Multivariate Calculus And Machine Learning,

https://medium.com/fintechexplained/calculus-multivariate-calculus-and- machine-learning-242b9efcb41c

Requirements for Part A:

First, briefly summarise the central ideas of the two references;

Second, explain in your own words why Matrix Calculus is useful in optimisation;

No more than 500 words, including any additional references besides the two provided.