I'm afraid I resorted to memorizing (x+y)^2 is x^2 + 2 x y + y^2 and the like, sometimes using Pascal's triangle, another memory aid. Our teacher said we should not take calculus if we had to think about algebra. Not what you are asking about, but I can _remember_ better than _think_.
Don Guinn wrote: > When in beginning algebra class we were to "simplify" an expression. I > put "simplify" in quotes because sometimes I wondered if we didn't end > out with something more complicated than what we started with. But I > have tried to do the same thing with tacit expressions and I have > really had a lot of trouble. Maybe I just need practice, but I have to > rely on doing it like I did it in algebra class, with explicit x and > y. > > Here is my shot at "simplifying" your original statement using tacit > expressions. Looks awkward. Anybody have any suggestions? > > ([^2)+(2**)+(]^2) NB. (x^2)+(2*x*y)+(y^2) > ([^2)+(2*[*])+(]^2) > ([*[)+([*])+([*])+(]*]) NB. (x*x)+(x*y)+(x*y)+(y*y) > (([*[)+([*]))+([*])+(]*]) NB. ((x*x)+(x*y))+((x*y)+(y*y)) > ([*([+]))+(([+])*]) NB. (x*(x+y))+((x+y)*y) > ([*([+]))+(]*([+])) NB. (x*(x+y))+(y*(x+y)) > ([+])*([+]) NB. (x+y)*(x+y) > (+)*(+) > +*+ > *:@+ NB. (x+y)^2 > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
