## Functions

# Built-in Functions

Use the built-in functions `abs()`

, `round()`

, `sqrt()`

. A built-in function is
one that you don’t need to install and load a package to use. Use another
function, `help()`

, to learn how to use any of the functions that you don’t know
how to use appropriately. `help()`

takes one parameter, the name of the function
you want information about. E.g.,`help(round)`

.

- The absolute value of -15.5.
- 4.483847 rounded to one decimal place. The function
`round()`

takes two
arguments, the number to be rounded and the number of decimal places.
- 3.8 rounded to the nearest integer. You don’t have to specify the number of
decimal places in this case if you don’t want to, because
`round()`

will
default to using 0 if the second argument is not provided. Look at
`help(round)`

or `?round`

to see how this is indicated.
- Assign the value of the square root of 2.6 to a variable. Then round the
variable you’ve created to 2 decimal places and assign it to another
variable. Print out the rounded value.
- Do the same thing as task 4 (
*immediately above*), but instead of creating
the intermediate variable, perform both the square root and the round on a
single line by putting the `sqrt()`

call inside the `round()`

call.

[click here for output]