Cos(30°) = √3/2
Cosine — the x-coordinate of the corresponding unit-circle point, or adjacent/hypotenuse in a right triangle.
How to derive cos(30°)
In a 30-60-90 triangle with sides 1, √3, 2, the side adjacent to 30° has length √3, so cos(30°) = adjacent/hypotenuse = √3/2.
Unit-circle context
The angle 30° corresponds to π/6 radians and sits Quadrant I on the unit circle.
Other trig values at 30°
Related cos values
Frequently asked
- What is the exact value of cos(30°)?
- The exact value is √3/2. Its decimal approximation is 0.86603.
- How do you derive cos(30°)?
- In a 30-60-90 triangle with sides 1, √3, 2, the side adjacent to 30° has length √3, so cos(30°) = adjacent/hypotenuse = √3/2.
- What is 30° in radians?
- 30° equals π/6 radians (multiply degrees by π/180).
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