Kotlin Program to Find Square Root of a Number

In Kotlin, you can find the square root of a number using kotlin.math.sqrt() function like this: val result = sqrt(number).

Examples

Input16.0

Output4.0

Input25.0

Output5.0

Input0.0

Output0.0

How to Think About It

To find the square root of a number, think about what number multiplied by itself gives the original number. We use the built-in sqrt() function in Kotlin that does this calculation for us easily.

Algorithm

1

Get the input number from the user or define it in the program.

2

Use the <code>sqrt()</code> function from Kotlin's math library to calculate the square root.

3

Store the result in a variable.

4

Print or return the result.

Code

kotlin

import kotlin.math.sqrt

fun main() {
    val number = 16.0
    val result = sqrt(number)
    println("Square root of $number is $result")
}

Output

Square root of 16.0 is 4.0

Dry Run

Let's trace the example where the input number is 16.0 through the code.

1

Input number

number = 16.0

2

Calculate square root

result = sqrt(16.0) = 4.0

3

Print result

Output: Square root of 16.0 is 4.0

Step	Variable	Value
1	number	16.0
2	result	4.0
3	output	Square root of 16.0 is 4.0

Why This Works

Step 1: Import sqrt function

We import sqrt from kotlin.math to use the built-in square root function.

Step 2: Calculate square root

The sqrt() function takes a Double and returns its square root as a Double.

Step 3: Display result

We print the result using println to show the square root to the user.

Alternative Approaches

Using exponentiation operator

kotlin

import kotlin.math.pow

fun main() {
    val number = 16.0
    val result = number.pow(0.5)
    println("Square root of $number is $result")
}

This uses <code>pow(0.5)</code> to calculate the square root, which is mathematically equivalent but slightly less direct than <code>sqrt()</code>.

Using manual approximation (Babylonian method)

kotlin

fun sqrtApprox(number: Double): Double {
    var guess = number / 2
    repeat(10) {
        guess = (guess + number / guess) / 2
    }
    return guess
}

fun main() {
    val number = 16.0
    val result = sqrtApprox(number)
    println("Approximate square root of $number is $result")
}

This method approximates the square root using repeated averaging, useful if you want to avoid built-in functions.

Complexity: O(1) time, O(1) space

Time Complexity

The sqrt() function runs in constant time because it uses hardware or optimized library calls.

Space Complexity

Only a few variables are used, so space complexity is constant.

Which Approach is Fastest?

Using sqrt() is fastest and most readable; manual methods are slower and more complex.

Approach	Time	Space	Best For
Using sqrt()	O(1)	O(1)	Simple and fast calculation
Using pow(0.5)	O(1)	O(1)	Alternative math approach
Manual approximation	O(n) with n iterations	O(1)	Learning or avoiding built-ins