The Math.tan() static method returns the tangent of a number in radians.
Syntax
Math.tan(x)
Parameters
x- : A number representing an angle in radians.
Return value
The tangent of x. If x is Infinity, -Infinity, or NaN, returns NaN.
Note: Due to floating point precision, it's not possible to obtain the exact value π/2, so the result is always finite if not
NaN.
Description
Because tan() is a static method of Math, you always use it as Math.tan(), rather than as a method of a Math object you created (Math is not a constructor).
Examples
Using Math.tan()
Math.tan(-Infinity); // NaN
Math.tan(-0); // -0
Math.tan(0); // 0
Math.tan(1); // 1.5574077246549023
Math.tan(Math.PI / 4); // 0.9999999999999999 (Floating point error)
Math.tan(Infinity); // NaN
Math.tan() and π/2
It's not possible to calculate tan(π/2) exactly.
Math.tan(Math.PI / 2); // 16331239353195370
Math.tan(Math.PI / 2 + Number.EPSILON); // -6218431163823738
Using Math.tan() with a degree value
Because the Math.tan() function accepts radians, but it is often easier to work with degrees, the following function accepts a value in degrees, converts it to radians and returns the tangent.
function getTanDeg(deg) {
const rad = (deg * Math.PI) / 180;
return Math.tan(rad);
}