## What are R Built-in Functions?

### Answer:

### Explanation:

R comes with a rich set of built-in functions that are predefined and ready to use. These functions perform a variety of common tasks, such as mathematical calculations, data manipulation, statistical analysis, and more. Using built-in functions saves time and effort because they provide standardized, optimized implementations for many tasks.

```
# Examples of built-in functions in R
x <- c(1, 2, 3, 4, 5)
# Calculate the mean of x
mean_value <- mean(x)
print(mean_value) # Output: 3
# Calculate the sum of x
sum_value <- sum(x)
print(sum_value) # Output: 15
```

In this example, the built-in functions `mean()`

and `sum()`

are used to calculate the mean and sum of a numeric vector `x`

. These functions are essential tools in R, allowing you to perform complex operations with minimal code.

R’s built-in functions cover a wide range of applications, from basic arithmetic to advanced statistical modeling, making R a powerful and versatile programming language for data analysis.