∂/∂x( x A T + (A xT + (xT A−1 x)(xT y))

Ts are the transposes and -1 are the inverses.

I understand partial differentiation wrt a variable.

I understand the matrix algebra of multiplying x by the transpose of a matrix.

I found some matrix identities but they don't help me understand why. Just need a place to start.

Thanks for any help.