How to perform square root operation in javascript

In mathematics, the square root refers to extracting the square root of a value. The square root operation is very common in solving many mathematical problems, such as in physics, engineering, etc. In JavaScript, we can implement the square root operation by using the Math.sqrt() function. This article will introduce some basic JavaScript square root calculation methods.

1. Use the Math.sqrt() function

Among the built-in functions of JavaScript, the Math.sqrt() function can implement the square root operation. This function takes one argument and returns its square root.

The following is an example:

let num = 16;
let squareRoot = Math.sqrt(num);

console.log(squareRoot); // 输出4

Here we pass parameter 16 to the Math.sqrt() function and assign the return value to the variable squareRoot. Finally, print out the value of squareRoot, which is the square root of parameter 16.

2. Use the exponential operator

In ES6 and above, JavaScript provides the exponential operator**. We can implement the square root operation using the exponential operator. The exponentiation operator raises a number to a specified power.

For example, if we want to calculate the square root of 16, we can write like this:

let num = 16;
let squareRoot = num ** 0.5;

console.log(squareRoot); // 输出4

Here we use the exponential operator, which means raising num to the power of 0.5, which is the square root of num. Finally we assign the result to squareRoot and print out its value.

3. Use the Newton iteration method

The Newton iteration method is a method used to approximately solve the zero points of a function, and can also be used to implement square root operations.

The basic idea of ​​Newton's iteration method is to start from an initial value, perform iterative calculations, and finally converge to the zero point of the function. For a value that requires a square root, you can use this method to gradually approximate its square root. The following is the code for using the Newton iteration method to implement the square root operation:

function sqrt(num, precision) {
  let x = num;
  let d = 1;
  while ((x - num / x) > precision) {
    x = (x + num / x) / 2;
  }
  return x.toFixed(d);
}

let num = 16;
let squareRoot = sqrt(num, 0.0001);

console.log(squareRoot); // 输出4.0

The sqrt() function here accepts two parameters. The first parameter is the value to be squared and the second parameter is the iteration convergence. Accuracy. We initially assign a numerical value to x, and then use a while loop to iteratively calculate until it converges to the specified accuracy. Finally we return the value of x and preserve the number of digits using the toFixed() method.

Summary

The square root operation in JavaScript can be implemented through the Math.sqrt() function, exponential operator, and Newton iteration method. The use of square root operations can be widely used in mathematical operations and scientific calculations. These methods can help us implement square root operations more efficiently.

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