Cosine Calculator
Find cos(θ) for any angle in degrees or radians, with the exact value at multiples of 15° and the other five functions.
Change the values and press Calculate to work out your own figures.
Enter an angle and choose degrees or radians.
Show the working
- θ = 60° = 1.047197551 rad = π/3
- cos θ
- = 0.5
How to use it
Enter an angle and choose degrees or radians.
Enter the values you know (decimals, fractions, surds such as 2√5, or angles such as π/3 in radians). Show the working gives the rule used at each step.
Key facts
cos θ = adjacent ÷ hypotenuse
Exact values
At multiples of 15° the functions have exact values built from √2, √3 and √6, which the calculator shows alongside the decimal.
Questions
What is cos(60°)?
1/2.
Degrees or radians?
Choose the unit under the angle; radians can be typed with π, such as π/3.
Formulas
cos θ = adjacent ÷ hypotenuse
Sources
Limitations
- Angles can be typed in degrees or radians; radians may be written with π (π/3, 2pi/3).