In addition to the three basic trig functions we’ve already looked at (Sine, Cosine, Tangent), there are three other related functions. These are Secant, Cosecant, and Cotangent. These functions have similar meanings as the first three, in that they represent the ratios of various side lengths of a right angle triangle, and can be used to find angles or unknown side lengths. I will not go into extensive detail on these functions, as they are less commonly required, but I will show you what they mean. Please remember to click on the Like button if this is helpful, and be sure to follow me with the buttons on the right side!
So far, with the help of SOHCAHTOA, we have seen that:
Sine = opposite / hypotenuse
Cosine = adjacent / hypotenuse
Tangent = opposite / adjacent
These new functions are related to the originals because they represent the inverse ratios. (Of course, inverse means you swap the top and the bottom…)
Cosecant = hypotenuse / opposite… (compare to Sine)
Secant = hypotenuse / adjacent…… (compare to Cosine)
Cotangent = adjacent / opposite…… (compare to Tangent)
Also, these functions can be abbreviated: Cosecant = Csc, Secant = Sec, Cotangent = Cot.
At the middle school and high school math level, you will rarely have a need to use these functions, but it is good for you to know what they are. However, most trig problems at this stage can easily be solved with the original three functions. Just in case, though, it’s always good to know all the trig functions: sine, cosine, tangent, secant, cosecant, cotangent. If you’d be interested in additional material, a good place to start would be these links that explain secant, cosecant, and cotangent. You can also search that site for many other math concept explanations (just remember to come back here!)
Thanks for reading this quick “cheat sheet” version of these additional trig functions. Please remember to bookmark my site to come back again!