Cos 355 Degrees

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

What is cos 355°?

Answer

cos 355° ≈
0.9962

Angle in radians: 355° = 71π/36. The point of the angle is in quadrant IV, where cosine is positive.

≈ — rounded to 4 decimal places. cos 355° can't be written with square roots: 355° is not a multiple of 3°.

cos 355° = cos(360° − 5°) = cos 5° ≈ 0.9962

P(cos 355°, sin 355°) ≈ (0.9962, −0.0872)

xyOP

P(cos 355°, sin 355°) ≈ (0.9962, −0.0872)

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

All four functions of 355°
FunctionExact valueDecimal
sin 355°—≈ −0.0872
cos 355°—≈ 0.9962
tan 355°—≈ −0.0875
cot 355°—≈ −11.4301

Reference angle: cos 5° ≈ 0.9962

See Also

Recalculate with different values ↑

Cosine of nearby angles

Anglecos
341°≈ 0.9455
342°√(10 + 2√5)/4
345°(√6 + √2)/4
355°≈ 0.9962
360°1
390°√3/2
400°≈ 0.7660

FAQ

What is cos 355°?

cos 355° ≈ 0.9962

Why does cos 355° 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°. 355° is not, so no such exact form exists; the value is used as a decimal: cos 355° ≈ 0.9962.

Why does a calculator show −1.0000 for cos 355?

The calculator is in radian mode (RAD): it takes cos 355 as the cosine of 355 radians, cos 355 rad ≈ −1.0000. Switch it to degrees (DEG): cos 355° ≈ 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