Arccos of 0.55

Arcsin, Arccos, Arctan, Arccot
Function
x

What is arccos(0.55)?

Answer

arccos(0.55) ≈
56.6330° ≈ 0.9884 rad

Range: arccos x is an angle from 0° to 180°, so the answer is unique.

≈ — the value is not a table one; rounded to 4 decimal places.

arccos(0.55) is the angle α in [0°, 180°] with cos α = 0.55.

cos 56.6330° ≈ 0.5500

xyOP

α = arccos(0.55) ≈ 56.6330°

P ≈ (0.55, 0.8352)

P lies on the line x = 0.55 in the upper half of the circle, where sin α ≥ 0; highlighted: cos α = 0.55.

All four inverse functions of 0.55
FunctionDegreesRadians
arcsin(0.55)≈ 33.3670°≈ 0.5824
arccos(0.55)≈ 56.6330°≈ 0.9884
arctan(0.55)≈ 28.8108°≈ 0.5028
arccot(0.55)≈ 61.1892°≈ 1.0680

See Also

Recalculate with different values ↑

Arccosine of nearby values

xarccos x
1/3≈ 70.5288°
2/5≈ 66.4218°
1/260° = π/3
0.55≈ 56.6330°
4/7≈ 55.1501°
√3/3≈ 54.7356°
3/5≈ 53.1301°

FAQ

What is arccos(0.55)?

arccos(0.55) ≈ 56.6330° ≈ 0.9884 rad

How to convert arccos(0.55) to radians?

Multiply the angle in degrees by π/180: 56.6330° × π/180 ≈ 0.9884 rad.

Why does a calculator show 0.9884 for arccos(0.55)?

The calculator is in radian mode (RAD) and gives the angle in radians: arccos(0.55) ≈ 0.9884 rad. In degrees (DEG) it is ≈ 56.6330°.

See Also