To me a nemonic is supposed to provide an easy way to help you remember something It shouldn t be hard to remember or hard to remember how to use The second nemonic I feel is quite complicated has much information buried in it is hard to learn how it all goes together and takes a significant amount of memory to remember how to use all its various parts Given that is it really a nemonic A second thing I want to do is give for consideration the nemonic I learned way back when we used paper trig tables Sorry I do not know a reference for it And I can not edit it in because I don t know the markup here on Wiki It is OH AH Oh Ah Ah Oh HA HO Say it moderately fast Sine cosine tangent cotangent secant cosecant are O H A H Oh Ah Ah Oh H A H O Unlike the soa cah toa nemonic it gives all six common functions But I like to teach only the 1st three OH AH Oh Ah simple enough or even only the first two OH AH and have them students memorize only Sin Cos and Tan then have them learn and understand that tan sin cos and the last three are inverses of the 1st three It might sound a bit like a tongue twister at first but it only took a my high school trig class about 15 minutes to learn it and a good part of that time was laughter and it is silly enough to be memorable I still use it after 45 years and some of my today s students have picked it up too as the one they prefer over soh cah toa