# Probability Density Functions in R (Examples)

The tutorial shows examples of how you can use built-in Probability Density Functions (PDF) in R, including PDF for normal distribution (dnorm), uniform distribution (dunif), and exponential distribution (dexp).

## Example 1: PDF for Normal Distribution

Normal distribution PDF `dnorm()` in R returns the density of probability at 2. Note that it is standard normal distribution with mean = 0 and SD = 1.

```> dnorm(2)
 0.05399097```

We can see that 0.054 is the density of probability at point of 2. Visually, it is the value on Y-axis in the bell shape curve of normal distribution (see the figure below).

## Example 2: PDF for Uniform Distribution

Below, uniform distribution PDF `dunif()` in R returns the density of probability at x=0 and x=1.5.

```> dunif(1.5, min = -2, max = 2)
 0.25
>
> dunif(0, min = -2, max = 2)
 0.25```

As we can see above, both of them return 0.25. 0.25 is value on Y-asix corresponding with x=0 and x=1.5. To better understand that, we can plot the PDF function below to see them.

In the following R code, exponential distribution PDF `dexp()` in R returns the density of probability at x=1.
```> dexp(1, rate=1)