"The common element I find in most if not all of the problems that students have that I find most baffling is some kind of substitution... It seems like if I could understand this one problem that it might shed light on a lot of other things. Can anyone help?" - Shelley Walsh
"Can someone provide a motivator for studying de Moivre's theorem either (1) because the student will need it in a future math course he/she is likely to take, or (2) because of its application to real world problems?" - Norman Mikalac
"Indian 'tables' of planetary parameters are lists first appearing in treatises of the middle of the first millennium CE. The suggested re-datings of the Vedic texts to the fourth millennium BCE or earlier, which have been proposed in various forms over the past couple of centuries, are based on attributing a very high degree of precision to some statements in them about the relation of star positions to direction and seasons...." - Kim Plofker
Astronomical event-dating of the Vedic texts, Indian mathematicians after 1000 A.D., the heliocentric model of Aryabhata, Ptolemy and Copernicus, and more.