Hey, the guy is getting a business degree; I feel a kinship. I can tell you the calc I took has been totaly unused in the ensuing 25 years (damn, just realized I am that old; I will have to change my sig). I have developed spreadsheets to calculate the ROR on adjustable-rate mortgage seurities, and another to prepare asset-liability reports, and have had no instance to use calculus. And this includes the time I built a 500sf addition to the back of my house with a vaulted ceiling and a bastard hip roof that the inspector had to call his boss to check out.
The stone age didn't end for a lack of stones. Neither will the hydrocarbon age......