Arctan of −4/5
Arcsin, Arccos, Arctan, Arccot
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.
arctan(−4/5) = −arctan(4/5) ≈ −38.6598°
tan(−38.6598°) ≈ −0.8000
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.
| Function | Degrees | Radians |
|---|---|---|
| arcsin(−4/5) | ≈ −53.1301° | ≈ −0.9273 |
| arccos(−4/5) | ≈ 143.1301° | ≈ 2.4981 |
| arctan(−4/5) | ≈ −38.6598° | ≈ −0.6747 |
| arccot(−4/5) | ≈ 128.6598° | ≈ 2.2455 |
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See Also
- Sin, Cos, Tan, Cot of an Angle - Exact value in square roots and the decimal, with reduction to an acute angle on the unit circle
- Square Root Calculator - Calculate the square root of any number
- Simplify Square Root Calculator - Write any square root in simplest radical form, step by step
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Arctangent of nearby values
| x | arctan x |
|---|---|
| −√3 | −60° = −π/3 |
| −4/3 | ≈ −53.1301° |
| −1 | −45° = −π/4 |
| −4/5 | ≈ −38.6598° |
| −√3/3 | −30° = −π/6 |
| −0.3 | ≈ −16.6992° |
| 0 | 0° = 0 |