Cos 17 Degrees

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

What is cos 17°?

Answer

cos 17° ≈
0.9563

Angle in radians: 17° = 17π/180. The point of the angle is in quadrant I, where cosine is positive.

≈ — rounded to 4 decimal places. cos 17° can't be written with square roots: 17° is not a multiple of 3°.

P(cos 17°, sin 17°) ≈ (0.9563, 0.2924)

xyOP

P(cos 17°, sin 17°) ≈ (0.9563, 0.2924)

Highlighted: the projection on the x-axis — cosine, x ≈ 0.9563.

All four functions of 17°
FunctionExact valueDecimal
sin 17°—≈ 0.2924
cos 17°—≈ 0.9563
tan 17°—≈ 0.3057
cot 17°—≈ 3.2709

See Also

Recalculate with different values ↑

Cosine of nearby angles

Anglecos
14°≈ 0.9703
15°(√6 + √2)/4
16°≈ 0.9613
17°≈ 0.9563
18°√(10 + 2√5)/4
19°≈ 0.9455
20°≈ 0.9397

FAQ

What is cos 17°?

cos 17° ≈ 0.9563

Why does cos 17° 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°. 17° is not, so no such exact form exists; the value is used as a decimal: cos 17° ≈ 0.9563.

Why does a calculator show −0.2752 for cos 17?

The calculator is in radian mode (RAD): it takes cos 17 as the cosine of 17 radians, cos 17 rad ≈ −0.2752. Switch it to degrees (DEG): cos 17° ≈ 0.9563. In radians the value is never undefined: π is irrational, so a whole number of radians never lands exactly on an axis.

See Also