Oxyrhynchus papyrus (P.Oxy. I 29) showing fragment of Euclid's Elements from the Wikipedia entry for History of Geometry.
Click the papyrus for the English and Greek translations of Euclid's Elements, courtesy of the University of Texas.
CAPTION: "It was in his blood to go off on a tangent..."
Cartoon shows four figures labled cosx, sinx/cosx, sinx, cscx sitting at a table in a sunny room.
The sinx/cosx figure is shown saying, "...and then if you let P be the vector space of all polynomials of degree at most 2, all you have to do is take the appropriate subset and see if it..."