How to use this calculator
An inverse trigonometric function returns an angle from a trigonometric ratio. Because the original trigonometric functions repeat, a principal range is chosen to make each inverse single-valued. Both degree and radian equivalents are shown so the angle convention stays clear.
The method
Enter the values in the labeled fields, check the units or selected mode, and choose Calculate. The result includes the applicable working and a breakdown or visual when useful. Change an input and calculate again to update the result.
Inverse function: Arctan (inverse tangent) Value or fraction: 3/4 Result unit: Degrees
Principal inverse angle: 36.8698976458°
atan(0.75)
Scope and limitations
Real inputs only. Arcsin and arccos require a value between -1 and 1. Results are numerical principal angles, not a list of all periodic solutions.
Common questions
Is tan^-1 the same as 1/tan?
In inverse-trigonometry notation, tan^-1 usually means arctan. The reciprocal 1/tan is cotangent, a different function.
Why is my angle not the only possible one?
Periodic trigonometric equations can have many solutions. This tool returns the principal inverse angle.
References & further reading
External references provide background, not an endorsement of this implementation. See our methodology for numerical conventions and limitations.