| Property | Value |
|---|---|
| Hex Value | $BB1B |
| Categories | |
| Localizations |
|
normalpdf(
Overview
Computes the probability density function for the normal distribution at a specified x value for the specified μ and σ.
Availability: Token available everywhere.
Syntax
normalpdf(x[,μ,σ])
Arguments
| Name | Type | Optional |
|---|---|---|
| x | ||
| μ | Yes | |
| σ | Yes |
Location
2nd, distr, DISTR, 1:normalpdf(
Description
normalpdf( is the normal (Gaussian) probability density function.
Since the normal distribution is continuous, the value of normalpdf( doesn't represent an actual probability - in fact, one of the only uses for this command is to draw a graph of the normal curve. You could also use it for various calculus purposes, such as finding inflection points.
The command can be used in two ways: normalpdf(x) will evaluate the standard normal p.d.f. (with mean at 0 and a standard deviation of 1) at x, and normalpdf(x,μ,σ) will work for an arbitrary normal curve, with mean μ and standard deviation σ.
Formulas
For the standard normal distribution, normalpdf(x) is defined as
(1) \(\begin{align} \texttt{normalpdf}(x)=\frac1{\sqrt{2\pi\,}} \, e^{-\frac1{2}x^2} \end{align}\)
For other normal distributions, normalpdf( is defined in terms of the standard distribution:
(2) \(\begin{align} \texttt{normalpdf}(x,\mu,\sigma)=\frac{1}{\sigma} \, \texttt{normalpdf} \left(\frac{x-\mu}{\sigma}\right) \end{align}\)
Related Commands
Source: parts of this page were written by the following TI|BD contributors: burr, DarkerLine, GoVegan, thornahawk.
History
| Calculator | OS Version | Description |
|---|---|---|
| TI-83 | 0.01013 | Added |