Cos 90 Degrees
Sin, Cos, Tan, Cot of an Angle
What is cos 90°?
Answer
cos 90° =
0
Angle in radians: 90° = π/2. The point of the angle is on the y-axis: (0, 1).
P(cos 90°, sin 90°) = (0, 1)
P(cos 90°, sin 90°) = (0, 1)
The point lies on the y-axis, so its projection on the x-axis is 0: cos 90° = 0.
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 90°?
cos 90° = 0
Why is cos 90° equal to 0?
The point of 90° on the unit circle is (0, 1), and cosine is its the x-coordinate, so cos 90° = 0.
Why does a calculator show −0.4481 for cos 90?
The calculator is in radian mode (RAD): it takes cos 90 as the cosine of 90 radians, cos 90 rad ≈ −0.4481. Switch it to degrees (DEG): cos 90° = 0. 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 80 Degrees: Cosine of 80° on the Unit Circle
- Cos 81 Degrees: Cosine of 81° on the Unit Circle
- Cos 82 Degrees: Cosine of 82° on the Unit Circle
- Cos 83 Degrees: Cosine of 83° on the Unit Circle
- Cos 84 Degrees: Cosine of 84° on the Unit Circle
- Cos 85 Degrees: Cosine of 85° on the Unit Circle
- Cos 86 Degrees: Cosine of 86° on the Unit Circle
- Cos 87 Degrees: Cosine of 87° on the Unit Circle
- Cos 88 Degrees: Cosine of 88° on the Unit Circle
- Cos 89 Degrees: Cosine of 89° on the Unit Circle
- Cos 97 Degrees: Cosine of 97° on the Unit Circle
- Cos 98 Degrees: Cosine of 98° on the Unit Circle
- Cos 100 Degrees: Cosine of 100° on the Unit Circle
- Cos 101 Degrees: Cosine of 101° on the Unit Circle
- Cos 105 Degrees: Cosine of 105° on the Unit Circle
- Cos 106 Degrees: Cosine of 106° on the Unit Circle
- Cos 108 Degrees: Cosine of 108° on the Unit Circle
- Cos 110 Degrees: Cosine of 110° on the Unit Circle
- Cos 120 Degrees: Cosine of 120° on the Unit Circle
- Cos 125 Degrees: Cosine of 125° on the Unit Circle
- Косинус 90 градусов (cos 90°) на единичной окружности
- Coseno de 90 grados (cos 90°) en el círculo unitario
- Cosseno de 90 graus (cos 90°) no ciclo trigonométrico