# Browsing category triangles

## The trig identities you need to know for integration

There is one big-daddy among the trig identities that you need to learn right now, if you don't know it already: $$\sin^2(x) + \cos^2(x) = 1$$ This is the identity that nearly all of the others spring from. There are some more definitions: $tan(x) = \frac{\sin(x)}{\cos(x)}$, which is one of

## The Mystic Rose

pointed me at a puzzle by at MathsJam: or at the Science Punk blog. The question is: how many triangles are there in a 'Mystic Rose' shape like this one (right) - with six interconnected points. I reckon there are 110. I got this by splitting it up into different