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: realpart (<expr>) Returns the real part of <expr>. realpart and imagpart will work on expressions involving trigonometic and hyperbolic functions, as well as square root, logarithm, and exponentiation.