Cos 215 Degrees
Sin, Cos, Tan, Cot of an Angle
What is cos 215°?
Answer
cos 215° ≈
−0.8192
Angle in radians: 215° = 43π/36. The point of the angle is in quadrant III, where cosine is negative.
≈ — rounded to 4 decimal places. cos 215° can't be written with square roots: 215° is not a multiple of 3°.
cos 215° = cos(180° + 35°) = −cos 35° ≈ −0.8192
P(cos 215°, sin 215°) ≈ (−0.8192, −0.5736)
P(cos 215°, sin 215°) ≈ (−0.8192, −0.5736)
Highlighted: the projection on the x-axis — cosine, x ≈ −0.8192.
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 215°?
cos 215° ≈ −0.8192
Why does cos 215° 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°. 215° is not, so no such exact form exists; the value is used as a decimal: cos 215° ≈ −0.8192.
Why does a calculator show 0.1978 for cos 215?
The calculator is in radian mode (RAD): it takes cos 215 as the cosine of 215 radians, cos 215 rad ≈ 0.1978. Switch it to degrees (DEG): cos 215° ≈ −0.8192. 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 165 Degrees: Cosine of 165° on the Unit Circle
- Cos 167 Degrees: Cosine of 167° on the Unit Circle
- Cos 175 Degrees: Cosine of 175° on the Unit Circle
- Cos 179 Degrees: Cosine of 179° on the Unit Circle
- Cos 180 Degrees: Cosine of 180° on the Unit Circle
- Cos 195 Degrees: Cosine of 195° on the Unit Circle
- Cos 198 Degrees: Cosine of 198° on the Unit Circle
- Cos 200 Degrees: Cosine of 200° on the Unit Circle
- Cos 210 Degrees: Cosine of 210° on the Unit Circle
- Cos 211 Degrees: Cosine of 211° on the Unit Circle
- Cos 216 Degrees: Cosine of 216° on the Unit Circle
- Cos 225 Degrees: Cosine of 225° on the Unit Circle
- Cos 227 Degrees: Cosine of 227° on the Unit Circle
- Cos 234 Degrees: Cosine of 234° on the Unit Circle
- Cos 240 Degrees: Cosine of 240° on the Unit Circle
- Cos 252 Degrees: Cosine of 252° on the Unit Circle
- Cos 255 Degrees: Cosine of 255° on the Unit Circle
- Cos 270 Degrees: Cosine of 270° on the Unit Circle
- Cos 285 Degrees: Cosine of 285° on the Unit Circle
- Cos 288 Degrees: Cosine of 288° on the Unit Circle
- Косинус 215 градусов (cos 215°) на единичной окружности
- Coseno de 215 grados (cos 215°) en el círculo unitario
- Cosseno de 215 graus (cos 215°) no ciclo trigonométrico