Cos 5 Degrees

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

What is cos 5°?

Answer

cos 5° ≈
0.9962

Angle in radians: 5° = π/36. The point of the angle is in quadrant I, where cosine is positive.

≈ — rounded to 4 decimal places. cos 5° can't be written with square roots: 5° is not a multiple of 3°.

P(cos 5°, sin 5°) ≈ (0.9962, 0.0872)

xyOP

P(cos 5°, sin 5°) ≈ (0.9962, 0.0872)

Highlighted: the projection on the x-axis — cosine, x ≈ 0.9962.

All four functions of 5°
FunctionExact valueDecimal
sin 5°—≈ 0.0872
cos 5°—≈ 0.9962
tan 5°—≈ 0.0875
cot 5°—≈ 11.4301

See Also

Recalculate with different values ↑

Cosine of nearby angles

Anglecos
2°≈ 0.9994
3°≈ 0.9986
4°≈ 0.9976
5°≈ 0.9962
6°≈ 0.9945
7°≈ 0.9925
8°≈ 0.9903

FAQ

What is cos 5°?

cos 5° ≈ 0.9962

Why does cos 5° 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°. 5° is not, so no such exact form exists; the value is used as a decimal: cos 5° ≈ 0.9962.

Why does a calculator show 0.2837 for cos 5?

The calculator is in radian mode (RAD): it takes cos 5 as the cosine of 5 radians, cos 5 rad ≈ 0.2837. Switch it to degrees (DEG): cos 5° ≈ 0.9962. In radians the value is never undefined: π is irrational, so a whole number of radians never lands exactly on an axis.

See Also