Cos 160 Degrees

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

What is cos 160°?

Answer

cos 160° ≈
−0.9397

Angle in radians: 160° = 8π/9. The point of the angle is in quadrant II, where cosine is negative.

≈ — rounded to 4 decimal places. cos 160° can't be written with square roots: 160° is not a multiple of 3°.

cos 160° = cos(180° − 20°) = −cos 20° ≈ −0.9397

P(cos 160°, sin 160°) ≈ (−0.9397, 0.3420)

xyOP

P(cos 160°, sin 160°) ≈ (−0.9397, 0.3420)

Highlighted: the projection on the x-axis — cosine, x ≈ −0.9397.

All four functions of 160°
FunctionExact valueDecimal
sin 160°—≈ 0.3420
cos 160°—≈ −0.9397
tan 160°—≈ −0.3640
cot 160°—≈ −2.7475

Reference angle: cos 20° ≈ 0.9397

See Also

Recalculate with different values ↑

Cosine of nearby angles

Anglecos
145°≈ −0.8192
150°−√3/2
159°≈ −0.9336
160°≈ −0.9397
162°−√(10 + 2√5)/4
164°≈ −0.9613
165°−(√6 + √2)/4

FAQ

What is cos 160°?

cos 160° ≈ −0.9397

Why does cos 160° 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°. 160° is not, so no such exact form exists; the value is used as a decimal: cos 160° ≈ −0.9397.

Why does a calculator show −0.9756 for cos 160?

The calculator is in radian mode (RAD): it takes cos 160 as the cosine of 160 radians, cos 160 rad ≈ −0.9756. Switch it to degrees (DEG): cos 160° ≈ −0.9397. In radians the value is never undefined: π is irrational, so a whole number of radians never lands exactly on an axis.

See Also