A result: [formula]. Test it
by taking limits — each
variable to zero and to
infinity — and say whether
each limit makes physical
sense or reveals an error.

Check the Answer With Limiting Cases

Push the variables to extremes and see if the physics survives.

Prompt

Here's a physics result: [paste the formula]. Test it by taking limits — what happens as each variable goes to zero and to infinity — and tell me whether each limit makes physical sense or reveals an error.