What is the relation between torque and angular momentum?

Explanation

We have the expression for magnitude of angular momentum of a rigid body as `L=I omega`.
The expression for magnitude of torque on a rigid body is `tau=I alpha`
We can further write the expression for torque as
`tau=I(domega)/(dt):'( alpha=(d omega)/(dt))`........1
Where `omega` is angular velocity and `alpha` is angular acceleration. We can also write equation 1 as,
`tau=(d(Iomega))/(dt)=(dL)/(dt)`