DELTA ERFC

ERF

ERF —

Synopsis

ERF([lower limit,]upper_limit)

Description

ERF returns the error function. With a single argument ERF returns the error function, defined as

erf(x) = 2/sqrt(pi)* integral from 0 to x of exp(-t*t) dt.

If two arguments are supplied, they are the lower and upper limits of the integral.

  • If either lower_limit or upper_limit is not numeric a #VALUE! error is returned.
  • This function is upward-compatible with that in Excel. (If two arguments are supplied, Excel will not allow either to be negative.)

Examples

ERF(0.4) equals 0.428392355.

ERF(1.6448536269515/SQRT(2)) equals 0.90.

The second example shows that a random variable with a normal distribution has a 90 percent chance of falling within approximately 1.645 standard deviations of the mean.

See also

ERFC.

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