JavaScript Math sin()

In this tutorial, you will learn about the JavaScript Math.sin() method with the help of examples.

The sin() method computes the trigonometric sine of the specified angle and returns it.


// sine of the angle 1 
var value1 = Math.sin(1);

// Output: 0.8414709848078965

sin() Syntax

The syntax of the Math.sin() method is:


Here, sin() is a static method. Hence, we are accessing the method using the class name, Math.

sin() Parameter

The sin() method takes a single parameter:

  • angle - in radians whose sine value is to be calculated

sin() Return Value

The sin() method returns:

  • sine value of a given angle (in radians)
  • NaN (Not a Number) for a non-numeric argument

Example 1: JavaScript Math.sin()

// sine of the angle 5 let value1 = Math.sin(5);
// negative angles are allowed let value2 = Math.sin(-2);
console.log(value2); // Output: // -0.9589242746631385 // -0.9092974268256817

In the above example,

  • Math.sin(5) - computes the sine value of the angle 5
  • Math.sin(-2) - computes the sine value of the angle -2

Example 2: Math.sin() with Math Constants

// math constants can be used let value = Math.sin(Math.PI);
console.log(value); // Output: 1.2246467991473532e-16

In the above example, we have used the sin() method to compute the sine of the math constant PI.

Here, the output -1.2246467991473532e-16 represents -1.2246467991473532 * 10-16

Example 3: Math.sin() with Non-Numeric Arguments

let string = "David"

// sin() with string as argument let value = Math.sin(string);
console.log(value); // Output: NaN

In the above example, we have tried to calculate the sine value of the string "David". Hence, we get NaN as the output.

Example 4: Math.sin() with Infinity argument

// infinity as argument let value1 = Math.sin(Infinity);
// negative infinity as argument let value2 = Math.sin(-Infinity);
console.log(value2); // Output: // NaN // NaN

The sin() method doesn't treat infinity as a number so the method returns NaN with this argument.

Also, the sine of an infinite angle is indefinite, which can't be defined with a number.

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