Cos 89 Degrees

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

What is cos 89°?

Answer

cos 89° ≈
0.0175

Angle in radians: 89° = 89π/180. The point of the angle is in quadrant I, where cosine is positive.

≈ — rounded to 4 decimal places. cos 89° can't be written with square roots: 89° is not a multiple of 3°.

P(cos 89°, sin 89°) ≈ (0.0175, 0.9998)

xyOP

P(cos 89°, sin 89°) ≈ (0.0175, 0.9998)

Highlighted: the projection on the x-axis — cosine, x ≈ 0.0175.

All four functions of 89°
FunctionExact valueDecimal
sin 89°—≈ 0.9998
cos 89°—≈ 0.0175
tan 89°—≈ 57.2900
cot 89°—≈ 0.0175

See Also

Recalculate with different values ↑

Cosine of nearby angles

Anglecos
86°≈ 0.0698
87°≈ 0.0523
88°≈ 0.0349
89°≈ 0.0175
90°0
97°≈ −0.1219
98°≈ −0.1392

FAQ

What is cos 89°?

cos 89° ≈ 0.0175

Why does cos 89° 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°. 89° is not, so no such exact form exists; the value is used as a decimal: cos 89° ≈ 0.0175.

Why does a calculator show 0.5102 for cos 89?

The calculator is in radian mode (RAD): it takes cos 89 as the cosine of 89 radians, cos 89 rad ≈ 0.5102. Switch it to degrees (DEG): cos 89° ≈ 0.0175. In radians the value is never undefined: π is irrational, so a whole number of radians never lands exactly on an axis.

See Also