Matrix Derivation: What if the derivative, but matrices?

You're likely referring to matrix calculus or the derivative of a matrix-valued function. In essence, this involves extending the concept of differentiation to matrix-valued functions. The derivative of a matrix with respect to a scalar is straightforward - it's simply the matrix of derivatives of each element. However, when differentiating with respect to a matrix or vector, things get more complex, involving concepts like the Jacobian matrix and matrix derivatives.