[ben_w]

Reminds me of someone I knew at university whose T-shirt was the definite integral from 10 to 13 of 2x dx followed by a question mark.

[jwilk]

∫ 2x dx = x² + C

13² − 10² = 69

[rhn_mk1]

...9?

[saagarjha]

The answer is a nice, round number.

[8bitsrule]

https://www.integral-calculator.com/

[rhn_mk1]

duh. it does contain 9 tho.