Cos 159 Degrees
Sin, Cos, Tan, Cot of an Angle
What is cos 159°?
Answer
cos 159° ≈
−0.9336
Angle in radians: 159° = 53π/60. The point of the angle is in quadrant II, where cosine is negative.
≈ — rounded to 4 decimal places. An exact form of cos 159° in square roots exists, but it is unwieldy — nested radicals.
cos 159° = cos(180° − 21°) = −cos 21° ≈ −0.9336
P(cos 159°, sin 159°) ≈ (−0.9336, 0.3584)
P(cos 159°, sin 159°) ≈ (−0.9336, 0.3584)
Highlighted: the projection on the x-axis — cosine, x ≈ −0.9336.
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 159°?
cos 159° ≈ −0.9336
Is there an exact value of cos 159°?
Yes: 159° is a multiple of 3°, and the values of such angles can be written with square roots — but the expression is unwieldy, with nested radicals built from the values of 18° and 15° (3° = 18° − 15°). In practice the decimal is used: cos 159° ≈ −0.9336.
Why does a calculator show −0.3425 for cos 159?
The calculator is in radian mode (RAD): it takes cos 159 as the cosine of 159 radians, cos 159 rad ≈ −0.3425. Switch it to degrees (DEG): cos 159° ≈ −0.9336. 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 126 Degrees: Cosine of 126° on the Unit Circle
- Cos 127 Degrees: Cosine of 127° on the Unit Circle
- Cos 130 Degrees: Cosine of 130° on the Unit Circle
- Cos 134 Degrees: Cosine of 134° on the Unit Circle
- Cos 135 Degrees: Cosine of 135° on the Unit Circle
- Cos 140 Degrees: Cosine of 140° on the Unit Circle
- Cos 142 Degrees: Cosine of 142° on the Unit Circle
- Cos 144 Degrees: Cosine of 144° on the Unit Circle
- Cos 145 Degrees: Cosine of 145° on the Unit Circle
- Cos 150 Degrees: Cosine of 150° on the Unit Circle
- Cos 160 Degrees: Cosine of 160° on the Unit Circle
- Cos 162 Degrees: Cosine of 162° on the Unit Circle
- Cos 164 Degrees: Cosine of 164° on the Unit Circle
- 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
- Косинус 159 градусов (cos 159°) на единичной окружности
- Coseno de 159 grados (cos 159°) en el círculo unitario
- Cosseno de 159 graus (cos 159°) no ciclo trigonométrico