# Kotlin Class: MathUtils class with static functions

## Kotlin Class: Exercise-13 with Solution

Write a Kotlin program that creates a class 'MathUtils' with static functions to calculate the factorial, square root, and cube root of a number.

**Sample Solution:**

**Kotlin Code:**

```
class MathUtils {
companion object {
fun factorial(n: Int): Long {
if (n == 0 || n == 1) {
return 1
}
var result = 1L
for (i in 2..n) {
result *= i
}
return result
}
}
}
fun sqrt(n: Double): Double {
return Math.sqrt(n)
}
fun cbrt(n: Double): Double {
return Math.cbrt(n)
}
fun main() {
val number = 7
val factorial = MathUtils.factorial(number)
println("Factorial of $number is: $factorial")
val squareRoot = sqrt(number.toDouble())
println("Square root of $number is: $squareRoot")
val cubeRoot = cbrt(number.toDouble())
println("Cube root of $number is: $cubeRoot")
}
```

Sample Output:

Factorial of 7 is: 5040 Square root of 7 is: 2.6457513110645907 Cube root of 7 is: 1.9129311827723892

**Explanation:**

In the above exercise -

- First we define a class "MathUtils" and declare a "companion" object inside it. The companion object contains static functions. Inside the companion object, we define a function "factorial()" to calculate the factorial of a number using an iterative approach.
- We also define top-level functions "sqrt()" and "cbrt()" outside the "MathUtils" class. These functions use the Math.sqrt and Math.cbrt functions from the standard library to calculate the square root and cube root of a number, respectively.
- In the "main()" function, we calculate the factorial of a number using the MathUtils.factorial function. We also calculate the square root and cube root using the sqrt and cbrt top-level functions, respectively.

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