Maple 9 Learning Guide - Maplesoft

172 • Chapter 6: Evaluation and SimplificationNote that the order of the variables in the list determines the ordering ofthe expression.> sort( x^3*y + y^2*x^2, [x,y] );x 3 y + x 2 y 2> sort( x^3*y + y^2*x^2, [y,x] );y 2 x 2 + y x 3To sort the entire expression by lexicographic ordering, use the plexoption with the sort command.> sort( x + x^3 + w^5 + y^2 + z^4, [w,x,y,z], plex );w 5 + x 3 + x + y 2 + z 4Again, the order of the unknowns in the call to sort determines theordering.> sort( x + x^3 + w^5 + y^2 + z^4, [x,y,z,w], plex );x 3 + x + y 2 + z 4 + w 5The sort command can also sort lists. See 6.3 Structural Manipulations.Converting Between Equivalent FormsYou can write many mathematical functions in several equivalent forms.For example, you can express sin(x) in terms of the exponential function.The convert command can perform this and many other types ofconversions. For more information, refer to the ?convert help page.> convert( sin(x), exp );−12 I (e(x I) − 1e> convert( cot(x), sincos );(x I))