Development Ruby

Ruby methods ending in ! mean that the method makes in-place, or destructive, changes to an object, not to a copy of it.
Method(s)                                             Description
Math.acos, Math.acos!                                 Arc cosine
Math.acosh, Math.acosh!                               Hyperbolic arc cosine
Math.asin, Math.asin!                                 Arc sine
Math.asinh, Math.asinh                                Hyperbolic arc sine
Math.atan, Math.atan!, Math.atan2, Math.atan2!        Arc tangent; atan takes an x argument; atan2 takes an x and a y argument
Math.atanh, Math.atanh!                               Hyperbolic arc tangent
Math.cos, Math.cos!                                   Cosine
Math.cosh, Math.cosh                                  Hyperbolic cosine
Math.sin, Math.sin!                                   Sine
Math.erf                                              Error function
Match.erfc                                            Complementary error function
Math.exp, Math.exp!                                   Base x of Euler
Math.frexp                                            Normalized fraction and exponent
Math.hypot                                            Hypotenuse
Math.ldexp                                            Floating-point value corresponding to a given mantissa and exponent
Math.sinh, Math.sinh!                                 Hyperbolic sine
Math.sqrt, Math.sqrt!                                 Square root
Math.tan, Math.tan!                                   Tangent
Math.tanh, Math.tanh!                                 Hyperbolic tangent