fx-Calc v4.4.0.2 Portable | 21.5 Mbfx-Calc is actually one of the most advanced desktop calculators...
Key features:
definition and immediate calculation of functions with up to 5 variables
solves equations
function analysis combined with graphic result presentation
parametric sum and product calculation
integrated function library
integrated library for scientific constants
2D function plots including complex graphs
OpenGL accelerated 3D function plots
multiple plot and analysis...