Tangent Calculator

Calculate tangent (tan) values for angles or find angles from tangent values

Calculate Tangent Values

Enter the angle to calculate its tangent value

Tangent Result

1
tan(45°)
1
Exact Value

Calculation Breakdown:

Formula: tan(θ) = sin(θ) / cos(θ)

sin(45°): 0.70710678

cos(45°): 0.70710678

tan(45°): 0.70710678 / 0.70710678 = 1

Common Angle Examples

Tangent Reference Table

Angle (Degrees)Angle (Radians)Exact ValueDecimal
000
30°π/6√3/30.577
45°π/411
60°π/3√31.732
90°π/2UndefinedUndefined
180°π00
270°3π/2UndefinedUndefined

Tangent Properties

Definition

tan(θ) = opposite / adjacent = sin(θ) / cos(θ)

Domain

All real numbers except odd multiples of π/2

Range

All real numbers (-∞, +∞)

Period

π radians (180°)

Tangent Tips

Tangent is undefined when cosine equals zero

tan(θ) = tan(θ + 180°) - tangent has period 180°

tan(45°) = 1 is the most commonly used value

Negative angles: tan(-θ) = -tan(θ)

Used in slopes, angles, and right triangle calculations

Understanding the Tangent Function

What is Tangent?

The tangent function is one of the fundamental trigonometric functions. In a right triangle, tangent is the ratio of the opposite side to the adjacent side. On the unit circle, tangent represents the slope of the line from the origin to a point on the circle.

Key Applications

  • Calculating slopes and angles in geometry
  • Engineering and physics calculations
  • Navigation and surveying
  • Architecture and construction

Mathematical Properties

Basic Formula

tan(θ) = sin(θ) / cos(θ)

Right Triangle

tan(θ) = opposite / adjacent

Inverse Function

θ = arctan(x) = tan⁻¹(x)

Law of Tangents

The law of tangents relates the tangent of two angles of a triangle to the lengths of the opposite sides:

(a - b) / (a + b) = tan(½(α - β)) / tan(½(α + β))

Where a and b are side lengths, and α and β are the opposite angles.

Common Mistakes to Avoid

• Remember that tangent is undefined at 90°, 270°, etc. (when cos(θ) = 0)

• Don't confuse tangent with the geometric concept of a tangent line

• Be careful with angle units - always specify degrees or radians

• Remember that tangent has a period of 180° (π radians), not 360°