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: hipow (<expr>, <x>) Returns the highest explicit exponent of <x> in <expr>. <x> may be a variable or a general expression. If <x> does not appear in <expr>, hipow returns 0.

hipow does not consider expressions equivalent to expr. In particular, hipow does not expand expr, so hipow (<expr>, <x>) and hipow (expand (<expr>, <x>)) may yield different results.
Examples:
(%i1) hipow (y^3 * x^2 + x * y^4, x);
(%o1) 2
(%i2) hipow ((x + y)^5, x);
(%o2) 1
(%i3) hipow (expand ((x + y)^5), x);
(%o3) 5
(%i4) hipow ((x + y)^5, x + y);
(%o4) 5
(%i5) hipow (expand ((x + y)^5), x + y);
(%o5) 0(%o1) true (%i2)