Cosine Calculator Formula
Understand the math behind the cosine calculator. Each variable explained with a worked example.
Formulas Used
Cosine Val
cosine_val = cos(angle_deg * pi / 180)Sine Val
sine_val = sin(angle_deg * pi / 180)Tangent Val
tangent_val = tan(angle_deg * pi / 180)Variables
| Variable | Description | Default |
|---|---|---|
angle_deg | Angle (degrees)(deg) | 60 |
How It Works
Cosine Function
Definition
In a right triangle, cos(angle) = adjacent / hypotenuse.
On the unit circle, cos(angle) is the x-coordinate of the point at that angle.
Key Values
Worked Example
Calculate cos(60°).
- 01cos(60°) = 0.5
- 02sin(60°) = √3/2 ≈ 0.8660
- 03tan(60°) = √3 ≈ 1.7321
Frequently Asked Questions
What is the cosine function?
Cosine gives the ratio of the adjacent side to the hypotenuse in a right triangle, or the x-coordinate on the unit circle.
How are sine and cosine related?
sin²(x) + cos²(x) = 1 (Pythagorean identity). Also, cos(x) = sin(90° - x) and vice versa.
When is cosine zero?
Cosine equals zero at 90° and 270° (and every 180° offset from those).
Learn More
Guide
Trigonometry Basics - Complete Guide
Learn the fundamentals of trigonometry including sine, cosine, tangent, the unit circle, identities, and the laws of sines and cosines with practical examples.
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Open Cosine Calculator