Cos 1 Degree

Sin, Cos, Tan, Cot of an Angle
Function
Angle (°)

What is cos 1°?

Answer

cos 1° ≈
0.9998

Angle in radians: 1° = π/180. The point of the angle is in quadrant I, where cosine is positive.

≈ — rounded to 4 decimal places. cos 1° can't be written with square roots: 1° is not a multiple of 3°.

P(cos 1°, sin 1°) ≈ (0.9998, 0.0175)

xyOP

P(cos 1°, sin 1°) ≈ (0.9998, 0.0175)

Highlighted: the projection on the x-axis — cosine, x ≈ 0.9998.

All four functions of 1°
FunctionExact valueDecimal
sin 1°—≈ 0.0175
cos 1°—≈ 0.9998
tan 1°—≈ 0.0175
cot 1°—≈ 57.2900

See Also

Recalculate with different values ↑

Cosine of nearby angles

Anglecos
0°1
1°≈ 0.9998
2°≈ 0.9994
3°≈ 0.9986
4°≈ 0.9976
5°≈ 0.9962
6°≈ 0.9945

FAQ

What is cos 1°?

cos 1° ≈ 0.9998

Why does cos 1° 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°. 1° is not, so no such exact form exists; the value is used as a decimal: cos 1° ≈ 0.9998.

Why does a calculator show 0.5403 for cos 1?

The calculator is in radian mode (RAD): it takes cos 1 as the cosine of 1 radian, cos 1 rad ≈ 0.5403. Switch it to degrees (DEG): cos 1° ≈ 0.9998. In radians the value is never undefined: π is irrational, so a whole number of radians never lands exactly on an axis.

See Also