How Cot() Works in PostgreSQL

In PostgreSQL, cot() is a trigonometric function that returns the cotangent of the specified angle.

The angle is provided as an argument, specified in radians.

In trigonometry, in a right triangle, the cotangent of an angle is the length of the adjacent side divided by the length of the opposite side.

Syntax

The syntax goes like this:

cot(x)

Where x is a double precision value that is interpreted as number of radians.

Here’s an example to demonstrate how it works.

SELECT cot(1);

Result:

0.6420926159343308

The argument can contain a fractional component.

SELECT cot(1.2490);

Result:

0.33338419232963085

The argument can also be negative.

SELECT cot(-1.2490);

Result:

-0.33338419232963085

The argument can include expressions.

SELECT cot(.5 * .45);

Result:

4.369190092810183

Here’s an example that includes the pi() function.

SELECT cot(pi()/3);

Result:

0.577350269189626

The argument provided to cot() must be non-zero, as the cotangent of zero doesn’t exist.

Here’s the result I get when I pass zero as an argument.

SELECT cot(0);

Result:

Infinity

As mentioned, cot() accepts its argument in radians. To provide it in degrees, use the cotd() function.

The cotd() function works exactly the same as cot(), except that its argument is specified in degrees instead of radians.