### Sum of the Squares of the first 5 numbers Link to heading

In this post I will try to use the `map()`

and `reduce()`

functions to compute the sum of the squares of the first five numbers. The `map()`

function takes a function and an iterable as a parameter. The items of the iterable are fed to the function to create a new list. The `reduce()`

function also takes a function and an iterable as a parameter. However, this takes two arguments cumulatively to the items of iterable, from left to right, so as to reduce the iterable to a single value.

So, the first 5 numbers are 1, 2, 3, 4, 5. And, the first task would be to find the the squares of each of these numbers. Lets start with writing a simple function that finds the square of a number.

```
def sqr(x):
return x*x
```

Now, that we know how to find the squares, lets write a function that can find the sum of two numbers.

```
def sum(x,y):
return x+y
```

We can get the first 5 numbers using the `range()`

function into a list. The next step would be to find the square of each numbers. This can be achieved by passing each of the elements from the list into the `sqr()`

function using python’s built-in `map()`

function.

```
a = range(1,6)
squares = map(sqr, a)
```

Once, we have the the squares in a list, we would now want to add each of these items to find the sum of the squares.

```
sum_of_squares = reduce(sum, squares)
```

The full program listing

```
a = range(1,6)
def sqr(x):
return x*x
def sum(x,y):
return x+y
squares = map(sqr, a)
sum_of_squares = reduce(sum, squares)
```