Double Angle Trig Identity Solver

Double Angle Trig Identities calculator, computes sin (2u), cos (2u) and tan (2u) for given angle.

The formula used

sin(2u) = 2 sinu cosu

cos(2u) = 1 - 2sin2u = 2cos2u - 1

tan(2u) = 2tanu / [ 1 - tan2u ]

Double angle formulas are allowing the expression of trigonometric functions of angles equal to 2u in terms of u, the double angle formulas can simplify the functions and gives ease to perform more complex calculations.

The double angle formulas are useful for finding the values of unknown trigonometric functions. The double angle formulas can be elaborated to multiple angle functions using the angle sum formulas and then re-applying the double angle formulas.

👉 Proof of Double Angle Identities