Maple 9 Learning Guide - Maplesoft

200 • Chapter 6: Evaluation and SimplificationFor information about the operands of an expression, see this section,pages 188–193.Changing the Type of an ExpressionTo convert an expression to another type, use the convert command.Consider the Taylor series for sin(x).> f := sin(x);f := sin(x)> t := taylor( f, x=0 );t := x − 1 6 x3 + 1120 x5 + O(x 6 )For example, you cannot plot a series, you must use convert(...,polynom) to convert it into a polynomial approximation first.> p := convert( t, polynom );p := x − 1 6 x3 + 1120 x5Similarly, the title of a plot must be a string, not a general expression.You can use convert(..., string) to convert an expression to a string.> p_txt := convert( p, string );p_txt := “x-1/6*x^3+1/120*x^ 5”> plot( p, x=-4..4, title=p_txt );x–1/6*x^3+1/120*x^51.510.5–4 –3 –2 –1 0–0.51 2x3 4–1–1.5