Cos 12 Degrees

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

What is cos 12°?

Answer

cos 12° ≈
0.9781

Angle in radians: 12° = π/15. The point of the angle is in quadrant I, where cosine is positive.

≈ — rounded to 4 decimal places. An exact form of cos 12° in square roots exists, but it is unwieldy — nested radicals.

P(cos 12°, sin 12°) ≈ (0.9781, 0.2079)

xyOP

P(cos 12°, sin 12°) ≈ (0.9781, 0.2079)

Highlighted: the projection on the x-axis — cosine, x ≈ 0.9781.

All four functions of 12°
FunctionExact valueDecimal
sin 12°—≈ 0.2079
cos 12°—≈ 0.9781
tan 12°—≈ 0.2126
cot 12°—≈ 4.7046

See Also

Recalculate with different values ↑

Cosine of nearby angles

Anglecos
9°≈ 0.9877
10°≈ 0.9848
11°≈ 0.9816
12°≈ 0.9781
13°≈ 0.9744
14°≈ 0.9703
15°(√6 + √2)/4

FAQ

What is cos 12°?

cos 12° ≈ 0.9781

Is there an exact value of cos 12°?

Yes: 12° 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 12° ≈ 0.9781.

Why does a calculator show 0.8439 for cos 12?

The calculator is in radian mode (RAD): it takes cos 12 as the cosine of 12 radians, cos 12 rad ≈ 0.8439. Switch it to degrees (DEG): cos 12° ≈ 0.9781. In radians the value is never undefined: π is irrational, so a whole number of radians never lands exactly on an axis.

See Also