JavaScript Math sin()

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

// Output: 0.8414709848078965

sin() Syntax

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

Math.sin(angle)

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);
console.log(value1);    

// 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);
console.log(value1);

// 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.

Recommended readings:

• JavaScript Math.cos()
• JavaScript Math.tan()
• JavaScript Math.asin()