I am using Symbolics on trig functions and simplifying is not simplifying. What rules do I need to implement. Here is the results of my unsimplified expressions.

If I simplify each term in the matrix using `simplify`

I get -

The [1,1] term is simplified to 1 but the [2,2] is `r^2`

, the [3,3] term is `r^2*sin(theta)^2`

, and all off diagonal terms are zero. I am not sure what rules I should implement to make this work and does simplify implement rules recursively?