JavaScript Math.cos() Method

Quiz

The JavaScript Math.cos() method accepts a numeric value (angle in radians) as a parameter and calculates the trigonometric cosine of the specified angle and returns it.

This method returns the cosine of specified angle in between "-1" and "1", inclusive. If the angle is "Infinity", "-Infinity", or "NaN", this method returns NaN as output.

Syntax

Following is the syntax of JavaScript Math.cos() method −

Math.cos(x);

Parameters

This method accepts only one parameter. The same is described below −

x: A numeric value representing an angle in radians.

Return value

This method returns the cosine value of the specified angle (x).

Example 1

In the following example, we are calculating the cosine value of the angle "5" using the JavaScript Math.cos() method −

<html>
<body>
<script>
   let number = Math.cos(5);
   document.write(number);
</script>
</body>
</html>

Output

After executing the above program, it returns "0.28366218546322625" as result.

Example 2

Here, we are computing the cosine value of the angle "0" −

<html>
<body>
<script>
   let number = Math.cos(0);
   document.write(number);
</script>
</body>
</html>

Output

It returns "1" as result.

Example 3

In this example, we are passing a mathematic constant PI (3.14) as a parameter to this method −

<html>
<body>
<script>
   let number = Math.cos(Math.PI);
   document.write(number);
</script>
</body>
</html>

Output

The above program computes the cosine of PI and returns "-1" as result.

Example 4

The cosine of an infinite angle will be indefinite, that can't be defined with a number, so it returns "NaN" as result −

<html>
<body>
<script>
   let number1 = Math.cos(-Infinity);
   let number2 = Math.cos(Infinity);
   document.write(number1, "<br>", number2);
</script>
</body>
</html>

Output

It returns NaN as result.

Example 5

If we try to calculate the cosine value of a non-numeric value or empty number, it returns NaN as result −

<html>
<body>
<script>
   let value1 = Math.cos("Tutorialspoint");
   let value2 = Math.cos();
   document.write(value1, "<br>", value2);
</script>
</body>
</html>

Output

As we can see in the output, the above program returned NaN.

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