(quick search, didn't find the old ones, but similar to these)
https://mathematicaldaily.weebly.com/secant-cosecant-cotange...
https://www.pinterest.com/pin/enter-image-description-here--...
... which were not used in my education but whenever i saw them i wished they had been, they lay out a geometric interpretation of all of them. by "old" i mean "look like Leonardo drew them"
(quick search, didn't find the old ones, but similar to these)
https://mathematicaldaily.weebly.com/secant-cosecant-cotange...
https://www.pinterest.com/pin/enter-image-description-here--...
... which were not used in my education but whenever i saw them i wished they had been, they lay out a geometric interpretation of all of them. by "old" i mean "look like Leonardo drew them"