cos(a+b)
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
soma
About this calculator
The cosine sum formula calculator is a useful tool for calculating the sum of two angles in radians. It uses the formula cos(a+b) = cos(a)cos(b) - sin(a)sin(b), which is based on the properties of the cosine function.
This calculator is ideal for those who need to calculate the sum of two angles in advanced physics, engineering, or mathematics problems. It is also useful for verifying the validity of a trigonometric formula or theorem.
Note that the formula cos(a+b) = cos(a)cos(b) - sin(a)sin(b) only holds when the angles a and b are expressed in radians. If you are working with angles in degrees, you need to convert them to radians before using this formula.
Additionally, be careful when calculating the sum of two angles in cases where one of the angles is very large, as this can cause rounding or precision issues.
Frequently asked questions
Can I use the cosine sum formula calculator to calculate the sum of two angles in degrees?
No, you need to convert the angles from degrees to radians before using this formula.
Can I use the cosine sum formula calculator to verify the validity of a trigonometric formula or theorem?
Yes, you can use this calculator to verify the validity of a trigonometric formula or theorem.
Can I use the cosine sum formula calculator to calculate the sum of two angles when one of the angles is very large?
Be careful: in cases where one of the angles is very large, there is a risk of rounding or precision issues.