cos(2a)
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
duplo
About this calculator
The cos(2a) calculator is a useful tool for calculating the value of the cosine of a double angle. It uses the formula cos²a − sin²a, which is one of the most important trigonometric identities.
This calculator is particularly useful when you need to calculate the cosine of a double angle in problems of advanced physics, engineering or mathematics. It's also useful for verifying your answer in exam questions or tests.
Remember to be careful when calculating the cosine of a double angle, as trigonometric identities can lead to surprising results. Make sure you understand the formula and the cases in which it applies before calculating.
Frequently asked questions
What is the cosine of a double angle?
The cosine of a double angle is a value that can be calculated using the formula cos²a − sin²a. It's useful in problems of advanced physics, engineering or mathematics.
When should I use this calculator?
Use this calculator when you need to calculate the cosine of a double angle in problems of physics, engineering or advanced mathematics. It's also useful for verifying the correct answer in exam questions or tests.
How can I use this calculator safely?
Make sure you understand the formula and the cases in which it applies before calculating. Also, verify that you're using the calculator correctly and that the results make sense in the context of the problem.