# Double angle calculator

To find double angles, enter the angle, select degree or radian, choose double angle i.e, sin(2θ), cos(2θ), or tan(2θ), and click calculate button

## Double Angle Identities Calculator

Double angle calculator used to calculate Double angle formula which refers to the expression of trigonometric functions of angles equal to in terms of θ.

## What is a double-angle identity?

A set of formulas that express trigonometric functions of twice an angle in terms of the trigonometric functions of the original angle is called a double angle identity. Double-angle formulas are especially useful in finding the values of unknown trigonometric functions.

## Double angle formulas

• sin(2θ) = 2 sinθ cosθ
• cos(2θ) = 1 - 2sin2θ
• tan(2θ) = 2 tanθ / 1 - tan2θ

## How to Calculate Double Angle Identities?

1. Determine which trigonometric function (e.g., sin, cos, or tan), you need to calculate for the double angle.
2. Place the value of the original angle (θ) in degrees or radians into the corresponding double-angle formula.
3. Simplify the expression to find the trigonometric value of the double angle.

Example:

Find the double angle trigonometric identity for sinθ if the angle is 30 in degrees.

Solution:

Apply formula:

Sin (2θ) = 2 x sinθ x cosθ

Sin (2 30) = 2  sin(30)  cos(30)

Sin (60) = 0.866025