Cos 64 Degrees
Sin, Cos, Tan, Cot of an Angle
What is cos 64°?
Answer
cos 64° ≈
0.4384
Angle in radians: 64° = 16π/45. The point of the angle is in quadrant I, where cosine is positive.
≈ — rounded to 4 decimal places. cos 64° can't be written with square roots: 64° is not a multiple of 3°.
P(cos 64°, sin 64°) ≈ (0.4384, 0.8988)
P(cos 64°, sin 64°) ≈ (0.4384, 0.8988)
Highlighted: the projection on the x-axis — cosine, x ≈ 0.4384.
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 64°?
cos 64° ≈ 0.4384
Why does cos 64° 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°. 64° is not, so no such exact form exists; the value is used as a decimal: cos 64° ≈ 0.4384.
Why does a calculator show 0.3919 for cos 64?
The calculator is in radian mode (RAD): it takes cos 64 as the cosine of 64 radians, cos 64 rad ≈ 0.3919. Switch it to degrees (DEG): cos 64° ≈ 0.4384. 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 54 Degrees: Cosine of 54° on the Unit Circle
- Cos 55 Degrees: Cosine of 55° on the Unit Circle
- Cos 56 Degrees: Cosine of 56° on the Unit Circle
- Cos 57 Degrees: Cosine of 57° on the Unit Circle
- Cos 58 Degrees: Cosine of 58° on the Unit Circle
- Cos 59 Degrees: Cosine of 59° on the Unit Circle
- Cos 60 Degrees: Cosine of 60° on the Unit Circle
- Cos 61 Degrees: Cosine of 61° on the Unit Circle
- Cos 62 Degrees: Cosine of 62° on the Unit Circle
- Cos 63 Degrees: Cosine of 63° on the Unit Circle
- Cos 65 Degrees: Cosine of 65° on the Unit Circle
- Cos 66 Degrees: Cosine of 66° on the Unit Circle
- Cos 67 Degrees: Cosine of 67° on the Unit Circle
- Cos 68 Degrees: Cosine of 68° on the Unit Circle
- Cos 69 Degrees: Cosine of 69° on the Unit Circle
- Cos 70 Degrees: Cosine of 70° on the Unit Circle
- Cos 71 Degrees: Cosine of 71° on the Unit Circle
- Cos 72 Degrees: Cosine of 72° on the Unit Circle
- Cos 73 Degrees: Cosine of 73° on the Unit Circle
- Cos 74 Degrees: Cosine of 74° on the Unit Circle
- Косинус 64 градусов (cos 64°) на единичной окружности
- Coseno de 64 grados (cos 64°) en el círculo unitario
- Cosseno de 64 graus (cos 64°) no ciclo trigonométrico