Saluton! Extmath is an attemt to make the Math more complete by providing additional constants and functions (for convenience all functions provided by Math are available as Extmath functions, too). Follows overview: CONSTANTS [ C | E | PI ] METHODS Powers and roots [ hypot | pwr | root | sqr | sqrt ] Exponential and logarithmic functions [ exp | exp10 | exp2 | frexp | ldexp | log | log10 | log2 ] Trigonometric functions [ acos | acot | acsc | asec | asin | atan | atan2 | cos | cot | csc | sec | sin | tan ] Hyperbolic functions [ acosh | acoth | acsch | asech | asinh | atanh | cosh | coth | csch | sech | sinh | tanh ] Special functions [ beta | erf | erfc | gamma | ln_gamma | sinc ] Absolute value, sign and rounding [ abs | ceil | floor | round | sign ] Integer functions [ delta | epsilon | factorial | gcd | lcm ] Solver [ linsolve | sqsolve ] C is Euler's constant 0.5772... acsc is arcus cosecans beta is Beta function gamma is Gamma function (generalized factorial) asec is arcus secans csc is cosecans sec is secans acsch is area cosecans hyperbolicus asech is area secans hyperbolicus csch is cosecans hyperbolicus sech is secans hyperbolicus sinc is sinc function (sin(x)/x) abs is absolute value sign is sign delta is Kronecker symbol epsilon is Levi-Civita symbol gcd is greatest common divisor lcm is least common multiple pwr is functional x**y root is functional x**(1/y) linsolve solves 'ax+b=c' sqsolve finds real-valued solutions of 'ax^2 + bx + c = d' presently all functions not in Math are known to work for real numbers (at all 464 assertions say so). I can't say anything about complex numbers because there are no test cases for them. If something doesn't work right please send test cases that fail. Comments are welcome, please send them to jupp (at) rubyforge (dot) org. More on extmath: Homepage: http://extmath.rubyforge.org/ Download: http://rubyforge.org/projects/extmath/ Gis, Josef 'Jupp' Schugt Mayan date: 12.19.10.09.15, 05 Men, 03 Mol