JavaScript Math sin()

The JavaScript Math.sin() function returns the sine of a specified number.

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

Math.sin(x)

sin(), being a static method, is called using the Math class name.


Math.sin() Parameters

The Math.sin() function takes in:

  • x - A number (in radians) whose sine value is required.

Return value from Math.sin()

  • Returns the sine of a given angle (a numeric value between -1 and 1).

Example 1: Using Math.sin()

// sine of 1 radian
var value1 = Math.sin(1);
console.log(value1); // Output: 0.8414709848078965

// negative radians are allowed
var value2 = Math.sin(-2);
console.log(value2); // Output: -0.9092974268256817

// Math constants can be used
var value3 = Math.sin(Math.PI / 2);
console.log(value3); // Output: 1

Output

0.8414709848078965
-0.9092974268256817
1

Example 2: Using Math.sin() with degrees

// custom function for angle in degrees
function sin(degrees) {
  var radians = (degrees * Math.PI) / 180;
  return Math.sin(radians);
}

// sine of 57 degrees
value1 = sin(57);
console.log(value1); // Output: 0.8386705679454239

// sine of negative degrees
value2 = sin(-90);
console.log(value2); // Output: -1

value3 = sin(90);
console.log(value3); // Output: 1

Output

0.8386705679454239
-1
1

Here, we have defined a sin() function that converts the degree value to radian and then passes it to Math.sin().

We can define custom functions in similar ways to extend the capabilities of such built-in functions.


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