Secant, Co-Secant, and Co-Tangent: the "other three" trig functions
Conceptually, these three functions aren't mind-blowing after you've seen sine, co-sine and tangent, so they don't usually give kids a ton of trouble. Don't underestimate them, though: these badboys aren't buttons on your calculator, and they force you to do tons of fractions and rationalizing of denominators. On the bright side, flexing your algebra muscles here is going to pay dividends later when we get to trig proofs later on.
Introducing Secant, Co-Secant & Co-Tangent
ChoShaCao is one way to go, but let's face it, nobody except for one Brentwood student I know has ever done it. Instead, we'll always use the reciprocals method to find these puppies, since that will work in special and non-special triangles. We'll also get tons of practice rationalizing denominators, since that's usually the hardest thing about finding sec, csc & cot.
Csc, Sec & Cot Example Problems
If you're already a ChoShaCao master, perhaps you'll find this video a touch boring. But if you're in the 99% of trig students who find solving triangles and denominator-rationalizing confusing, by all means stick around, and you too can be bored by these "find the six trigonometric functions" questions!
Using a calculator on Secant, Co-Secant, Co-Tangent
These aren't buttons on your calculator, but they obviously should be. This video shows you how to fix what TI broke, turning your calculator into a powerful tool in your pursuit of better trig grades. (HINT: Main trick here is not to get burned by that little "-1" above the sine and cosine buttons, which don't mean reciprocal!)