Texas Instruments voyage 200 User Manual - Page 849

part(expression1, n) ⇒ expression part(cos(pù x+3),1) ¸ 3+pøx Simplifies expression1 and returns the nth argument or operand, where n is > 0 and  the number of top-level arguments or operands returned by part(expression1). Otherwise, an error is returned. Note: Simplification changed the order of the argument. By combining the variations of part(), you can extract all of the sub-expressions in the simplified result of expression1. As shown in the example to the right, you can store an argument or operand and then use part() to extract further subexpressions. Note: When using part(), do not rely on any particular order in sums and products. part(cos(pù x+3)) ¸ part(cos(pù x+3),0) ¸ part(cos(pù x+3),1)! temp ¸ temp ¸ part(temp,0) ¸ part(temp) ¸ part(temp,2) ¸ part(temp,1)! temp ¸ part(temp,0) ¸ part(temp) ¸ part(temp,1) ¸ part(temp,2) ¸ 1 "cos" 3+pøx pøx+3 "+" 2 3 pøx "ù " 2 p x Expressions such as (x+y+z) and (xì yì z) are part(x+y+z) ¸ 2 represented internally as (x+y)+z and (xì y)ì z. part(x+y+z,2) ¸ z This affects the values returned for the first and part(x+y+z,1) ¸ y+x second argument. There are technical reasons why part(x+y+z,1) returns y+x instead of x+y. Similarly, xù yù z is represented internally as part(xù yù z) ¸ 2 (xù y)ù z. Again, there are technical reasons why part(xù yù z,2) ¸ z the first argument is returned as yøx instead of part(xù yù z,1) ¸ yøx xøy. When you extract sub-expressions from a matrix, part([a,b,c;x,y,z],0) ¸ "{" remember that matrices are stored as lists of lists, part([a,b,c;x,y,z]) ¸ 2 as illustrated in the example to the right. part([a,b,c;x,y,z],2)! temp ¸ {x y z} part(temp,0) ¸ "{" part(temp) ¸ 3 part(temp,3) ¸ z delVar temp ¸ Done Appendix A: Functions and Instructions 851