You can also pass the result of one function
as a parameter to another, for example, this
is how we first find the square of the number
`2`

, and then the square of the result:

```
function func(num) {
return num ** 2;
}
let res = func(func(2));
console.log(res); // shows 16
```

The functions, of course, do not have to be the same. Let, for example, we have a function that returns the square of a number, and a function that returns the cube of a number:

```
function square(num) {
return num ** 2;
}
function cube(num) {
return num ** 3;
}
```

Let's use these functions to square the number
`2`

, and then cube the result of this operation:

```
let res = cube(square(2));
console.log(res);
```

Suppose now we have a function that returns the square of a number, and a function that finds the sum of two numbers:

```
function square(num) {
return num ** 2;
}
function sum(num1, num2) {
return num1 + num2;
}
```

Using these functions, we find the sum of
the square of the number `2`

and the
square of the number `3`

:

```
let res = sum(square(2), square(3));
console.log(res);
```

Suppose you have a function that returns the square root of a number, and a function that rounds a fraction to three decimal places:

```
function sqrt(num) {
return Math.sqrt(num);
}
function round(num) {
return num.toFixed(3);
}
```

Use these functions to find the square
root of `2`

and round it to three
decimal places.

Suppose you have a function that returns the square root of a number and a function that returns the sum of three numbers:

```
function sqrt(num) {
return Math.sqrt(num);
}
function sum(num1, num2, num3) {
return num1 + num2 + num3;
}
```

Using these functions, find the sum of
the roots of the numbers `2`

, `3`

and `4`

and write it into
the variable `res`

.

Suppose you have a function that rounds a fraction to three decimal places:

```
function round(num) {
return num.toFixed(3);
}
```

Use this function to modify the previous
task so that the variable `res`

is
set to a fraction rounded to `3`

decimal places.