Arctan of 4/5

Arcsin, Arccos, Arctan, Arccot
Function
x

What is arctan(4/5)?

Answer

arctan(4/5) ≈
38.6598° ≈ 0.6747 rad

Range: arctan x is an angle strictly between −90° and 90°, so the answer is unique.

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

4/5 = 0.8.

arctan(4/5) is the angle α in (−90°, 90°) with tan α = 4/5.

tan 38.6598° ≈ 0.8000

xyOPT

α = arctan(4/5) ≈ 38.6598°

P ≈ (0.7809, 0.6247)

T(1, 4/5) is where line OP meets the line x = 1; highlighted: tan α = 4/5.

All four inverse functions of 4/5
FunctionDegreesRadians
arcsin(4/5)≈ 53.1301°≈ 0.9273
arccos(4/5)≈ 36.8699°≈ 0.6435
arctan(4/5)≈ 38.6598°≈ 0.6747
arccot(4/5)≈ 51.3402°≈ 0.8961

See Also

FAQ

What is arctan(4/5)?

arctan(4/5) ≈ 38.6598° ≈ 0.6747 rad

How to convert arctan(4/5) to radians?

Multiply the angle in degrees by π/180: 38.6598° × π/180 ≈ 0.6747 rad.

Why does a calculator show 0.6747 for arctan(4/5)?

The calculator is in radian mode (RAD) and gives the angle in radians: arctan(4/5) ≈ 0.6747 rad. In degrees (DEG) it is ≈ 38.6598°.