Cos 20 Degrees
Sin, Cos, Tan, Cot of an Angle
What is cos 20°?
Answer
cos 20° ≈
0.9397
Angle in radians: 20° = π/9. The point of the angle is in quadrant I, where cosine is positive.
≈ — rounded to 4 decimal places. cos 20° can't be written with square roots: 20° is not a multiple of 3°.
P(cos 20°, sin 20°) ≈ (0.9397, 0.3420)
P(cos 20°, sin 20°) ≈ (0.9397, 0.3420)
Highlighted: the projection on the x-axis — cosine, x ≈ 0.9397.
See Also
- Arcsin, Arccos, Arctan, Arccot - The angle from the value of its sine, cosine, tangent or cotangent: exact in degrees and π, with the check and the unit circle
- Square Root Calculator - Calculate the square root of any number
- Simplify Square Root Calculator - Write any square root in simplest radical form, step by step
- Geometry Formulas: Area, Volume, Perimeter - The formula for every standard shape, where it comes from, and worked examples
Cosine of nearby angles
FAQ
What is cos 20°?
cos 20° ≈ 0.9397
Why does cos 20° have no exact value?
A trigonometric value of a whole number of degrees can be written with square roots only when the angle is a multiple of 3°. 20° is not, so no such exact form exists; the value is used as a decimal: cos 20° ≈ 0.9397.
Why does a calculator show 0.4081 for cos 20?
The calculator is in radian mode (RAD): it takes cos 20 as the cosine of 20 radians, cos 20 rad ≈ 0.4081. Switch it to degrees (DEG): cos 20° ≈ 0.9397. In radians the value is never undefined: π is irrational, so a whole number of radians never lands exactly on an axis.
See Also
- Cos 10 Degrees: Cosine of 10° on the Unit Circle
- Cos 11 Degrees: Cosine of 11° on the Unit Circle
- Cos 12 Degrees: Cosine of 12° on the Unit Circle
- Cos 13 Degrees: Cosine of 13° on the Unit Circle
- Cos 14 Degrees: Cosine of 14° on the Unit Circle
- Cos 15 Degrees: Cosine of 15° on the Unit Circle
- Cos 16 Degrees: Cosine of 16° on the Unit Circle
- Cos 17 Degrees: Cosine of 17° on the Unit Circle
- Cos 18 Degrees: Cosine of 18° on the Unit Circle
- Cos 19 Degrees: Cosine of 19° on the Unit Circle
- Cos 21 Degrees: Cosine of 21° on the Unit Circle
- Cos 22 Degrees: Cosine of 22° on the Unit Circle
- Cos 23 Degrees: Cosine of 23° on the Unit Circle
- Cos 24 Degrees: Cosine of 24° on the Unit Circle
- Cos 25 Degrees: Cosine of 25° on the Unit Circle
- Cos 26 Degrees: Cosine of 26° on the Unit Circle
- Cos 27 Degrees: Cosine of 27° on the Unit Circle
- Cos 28 Degrees: Cosine of 28° on the Unit Circle
- Cos 29 Degrees: Cosine of 29° on the Unit Circle
- Cos 30 Degrees: Cosine of 30° on the Unit Circle
- Косинус 20 градусов (cos 20°) на единичной окружности
- Coseno de 20 grados (cos 20°) en el círculo unitario
- Cosseno de 20 graus (cos 20°) no ciclo trigonométrico