Online Algebra Calculator
Many of users do not use powerful Maxima computer algebra system for systematic work, but for ad hoc algebraic calculations – equations, functions, matrixes, etc. only. To do this job, it is not useful to download the whole application from a web site.
Function: pickapart (<expr>, <n>) Assigns intermediate expression labels to subexpressions of <expr> at depth <n>, an integer. Subexpressions at greater or lesser depths are not assigned labels. pickapart returns an expression in terms of intermediate expressions equivalent to the original expression <expr>.

See also part, dpart, lpart, inpart, and reveal.
Examples:
(%i1) expr: (a+b)/2 + sin (x^2)/3 - log (1 + sqrt(x+1));
2
sin(x ) b + a
(%o1) - log(sqrt(x + 1) + 1) + ------- + -----
3 2
(%i2) pickapart (expr, 0);2 sin(x ) b + a
(%t2) - log(sqrt(x + 1) + 1) + ------- + -----
3 2
(%o2) %t2
(%i3) pickapart (expr, 1);(%t3) - log(sqrt(x + 1) + 1)
2 sin(x )
(%t4) -------
3
b + a
(%t5) -----
2 (%o5) %t5 + %t4 + %t3
(%i5) pickapart (expr, 2);(%t6) log(sqrt(x + 1) + 1)
2
(%t7) sin(x )
(%t8) b + a %t8 %t7
(%o8) --- + --- - %t6
2 3
(%i8) pickapart (expr, 3);(%t9) sqrt(x + 1) + 1
2
(%t10) x b + a sin(%t10)
(%o10) ----- - log(%t9) + ---------
2 3
(%i10) pickapart (expr, 4);(%t11) sqrt(x + 1)
2
sin(x ) b + a
(%o11) ------- + ----- - log(%t11 + 1)
3 2
(%i11) pickapart (expr, 5);(%t12) x + 1
2
sin(x ) b + a
(%o12) ------- + ----- - log(sqrt(%t12) + 1)
3 2
(%i12) pickapart (expr, 6);
2
sin(x ) b + a
(%o12) ------- + ----- - log(sqrt(x + 1) + 1)
3 2(%o1) true (%i2)