MySQL ACOS() Function

The ACOS() function in MySQL calculates the arccosine (inverse cosine) of a number. The arccosine of a number is the angle whose cosine is that number. The result is an angle expressed in radians.

ACOS(): Definition and Usage

ACOS() is a mathematical function primarily used in trigonometry and related fields. It's the inverse of the COS() function. Remember that the input number (the value whose arccosine you're finding) must be between -1 and 1 (inclusive); otherwise, the function will return NULL.

Syntax


ACOS(number)

Parameter Values

Parameter	Description
`number`	The numeric value for which you want to compute the arccosine (must be between -1 and 1). This is required.

Examples

Calculating the Arccosine of a Positive Number

This example calculates the arccosine of 0.25.

Syntax


SELECT ACOS(0.25);

Output


1.3181160716528 (Result in radians)

Calculating the Arccosine of a Negative Number

This example demonstrates calculating the arccosine of -0.8.

Syntax


SELECT ACOS(-0.8);

Output


2.49809154478799 (Result in radians)