A math joke (and a food joke) is:

*Q: What is the first derivative of a cow?
A: Prime rib.*

The joke has been cited in print since at least 2004 and has been printed on many images.

Octopus Overlords

Stupid Math Jokes Wanted

by Guy Incognito » Tue Nov 16, 2004 3:05 pm

(...)

Q: What is the first derivative of a cow?

A: Prime Rib!

Google Groups: silverBULLET

Math jokes

*Myth*

1/22/05

(...)

Q: What is the first derivative of a cow?

A: Prime Rib!

Google Groups: novell.community.chat

Re: Why?

*Kim Groneman*

10/27/06

(...)

Q: What is the first derivative of a cow?

A: Prime Rib!

Exodus (josh)

@tehEx0dus

Q: What is the first derivative of a cow?

A: Prime Rib!

10:19 AM - 21 Nov 2008

4 December 2008,

*The Daily Oklahoman*(Oklahoma City, OK), “Google, and be stupid” by David Zizzo, pg. 4E, col. 4:

What is the first derivative of a cow? Prime rib.

Shamrock

@Shambo

Shammy’s Math Lesson: The first derivative of a cow is its prime rib.

9:06 AM - 11 Dec 2008

Google Books

*Country Hardball*

By Steve Weddle

Blue Ash, OH: Tyrus Books

2013

Pg. 154:

And then he thought about how the girl who wrote that note to him, who’d laughed when he’d told her the first derivative of a cow was prime rib, how he’d never be with her.

Google Books

*The Tragic Age:*

A Novel

A Novel

By Stephen Metcalfe

New York, NY: St. Martin’s Griffin

2015

Pg. 46:

“What is the first derivative of a cow?” he’ll says. “Prime rib.”

No one laughs.

Reddit—Jokes

What is the first derivative of a cow?

submitted August 21, 2016 by Kenzlea

A prime rib.