Cos 28 Degrees
Sin, Cos, Tan, Cot of an Angle
What is cos 28°?
Answer
cos 28° ≈
0.8829
Angle in radians: 28° = 7π/45. The point of the angle is in quadrant I, where cosine is positive.
≈ — rounded to 4 decimal places. cos 28° can't be written with square roots: 28° is not a multiple of 3°.
P(cos 28°, sin 28°) ≈ (0.8829, 0.4695)
P(cos 28°, sin 28°) ≈ (0.8829, 0.4695)
Highlighted: the projection on the x-axis — cosine, x ≈ 0.8829.
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 28°?
cos 28° ≈ 0.8829
Why does cos 28° 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°. 28° is not, so no such exact form exists; the value is used as a decimal: cos 28° ≈ 0.8829.
Why does a calculator show −0.9626 for cos 28?
The calculator is in radian mode (RAD): it takes cos 28 as the cosine of 28 radians, cos 28 rad ≈ −0.9626. Switch it to degrees (DEG): cos 28° ≈ 0.8829. 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 18 Degrees: Cosine of 18° on the Unit Circle
- Cos 19 Degrees: Cosine of 19° on the Unit Circle
- Cos 20 Degrees: Cosine of 20° 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 29 Degrees: Cosine of 29° on the Unit Circle
- Cos 30 Degrees: Cosine of 30° on the Unit Circle
- Cos 31 Degrees: Cosine of 31° on the Unit Circle
- Cos 32 Degrees: Cosine of 32° on the Unit Circle
- Cos 33 Degrees: Cosine of 33° on the Unit Circle
- Cos 34 Degrees: Cosine of 34° on the Unit Circle
- Cos 35 Degrees: Cosine of 35° on the Unit Circle
- Cos 36 Degrees: Cosine of 36° on the Unit Circle
- Cos 37 Degrees: Cosine of 37° on the Unit Circle
- Cos 38 Degrees: Cosine of 38° on the Unit Circle
- Косинус 28 градусов (cos 28°) на единичной окружности
- Coseno de 28 grados (cos 28°) en el círculo unitario
- Cosseno de 28 graus (cos 28°) no ciclo trigonométrico