- #1

- 901

- 3

## Homework Statement

L = lambda.

Prove: d(A^-1)/dL = -(A^-1)(dA/dL)(A^-1)

## Homework Equations

???

## The Attempt at a Solution

I did this as an analogy with function of numbers, but don't know how to extend this to matricies. for example:

lets say A = f(L)

d(f(L)^-1)/dL = - (f(L)^-2*d(f(L))/dL = -(A^-1)*dA/dL*(A^-1)

But what is the matrix form?