Learning Guide Learning Guide

3.1 Simple solve • 49–5–10–15–20–2550 55 60 65 70 75 80–56–58–52–54–48–50–44–46–42The unapply CommandFor convenience, define x = x(u, t), y = y(u, t), and z = z(u, t), thatis, convert the solutions to functions. Recall that you can easily select asolution expression for a particular variable using eval.> eval( x, s2 );− 52713 − 7 t − 2813 uHowever, this is an expression for x and not a function.> x(1,1);x(1, 1)To convert the expression to a function you need another importantcommand, unapply. To use it, provide unapply with the expression andthe independent variables. For example,> f := unapply(x^2 + y^2 + 4, x, y);f := (x, y) → x 2 + y 2 + 4produces the function, f, of x and y that maps (x, y) to x 2 + y 2 + 4.This new function is easy to use.> f(a,b);a 2 + b 2 + 4