To calculate result you have to disable your ad blocker first.

# 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

Table of Contents:

## 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 **2θ **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 - 2sin**^{2}θ**tan(2θ) = 2 tanθ / 1 - tan**^{2}θ

**How to Calculate Double Angle Identities?**

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