Accuracy[x] gives the effective number of digits to the right of the decimal point in the number x.
"Defining Variables" discussed assignments such as x=y which set x equal to y. Here we discuss equations, which test equality. The equation x==y tests whether x is equal to ...
$MachinePrecision gives the number of decimal digits of precision used for machine-precision numbers.
When Mathematica reads the text x^y, it interprets it as x raised to the power y. In a notebook, you can also give the two-dimensional input x^y directly. Mathematica again ...
MaxStepFraction is an option to functions like NDSolve that specifies the maximum fraction of the total range to cover in a single step.
DiscreteWaveletData[{wind_1 -> coef_1, ...}, wave, wtrans] yields a discrete wavelet data object with wavelet coefficients coef_i corresponding to wavelet index wind_i, ...
General issues about the internal implementation of Mathematica are discussed in "The Internals of Mathematica". Given here are brief notes on particular features. These ...
VarianceEstimatorFunction is an option for LinearModelFit and NonlinearModelFit which specifies the variance estimator to use.
QuantilePlot[list] generates a plot of quantiles of list against the quantiles of a normal distribution.QuantilePlot[dist] generates a plot of quantiles of the distribution ...
CoshIntegral[z] gives the hyperbolic cosine integral Chi(z).