JavaScript: Calculate the nth root of a number

JavaScript Math: Exercise-26 with Solution

Calculate nth Root of a Number

Write a JavaScript function to calculate the nth root of a number.

Test Data :
console.log(nthroot(64, 2));
8
console.log(nthroot(64, -2));
0.125

Sample Solution:

JavaScript Code:

// Define a function named nthroot that calculates the nth root of a given number.
function nthroot(x, n)
{
    // Determine if n is odd.
    ng = n % 2;
    // If n is odd or x is negative, make x positive.
    if((ng == 1) || x<0)
        x = -x;
    // Calculate the nth root of x.
    var r = Math.pow(x, 1 / n);
    // Raise r to the power of n.
    n = Math.pow(r, n);
  
    // Check if the difference between x and n is less than 1 and both x and n have the same sign.
    if(Math.abs(x - n) < 1 && (x > 0 === n > 0))
        // If n is odd, return -r, otherwise return r.
        return ng ? -r : r; 
}

// Output the result of calculating the square root of 64 to the console.
console.log(nthroot(64, 2));
// Output the result of calculating the square root of 64 with negative exponent to the console.
console.log(nthroot(64, -2));

Output:

8
0.125

Visual Presentation:

Flowchart:

Live Demo:

See the Pen javascript-math-exercise-26 by w3resource (@w3resource) on CodePen.

For more Practice: Solve these Related Problems:

• Write a JavaScript function that calculates the nth root of a number using exponentiation and handles fractional exponents.
• Write a JavaScript function that implements the nth root calculation iteratively using the Newton-Raphson method.
• Write a JavaScript function that validates inputs for nth root calculation and returns an error for invalid parameters.
• Write a JavaScript function that calculates the nth root and returns the result rounded to a specified precision.

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• JavaScript Math and Numbers Exercises Home ↩
• JavaScript Exercises Home ↩

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