x

A number representing an angle in radians.

The tangent of x. If x is Infinity, -Infinity, or NaN, returns NaN.

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).

It's not possible to calculate tan(π/2) exactly.

Math.tan(Math.PI / 2); // 16331239353195370
Math.tan(Math.PI / 2 + Number.EPSILON); // -6218431163823738

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);
}

• Math.acos()
• Math.asin()
• Math.atan()
• Math.atan2()
• Math.cos()
• Math.sin()