Inverse Trig Calculator
Calculate arcsin, arccos, and arctan with results in degrees and radians.
This tool is for informational and educational purposes only. It is not a substitute for professional financial, medical, legal, or engineering advice. See Terms of Service.
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Request a ToolHow to Use the Inverse Trig Calculator
This calculator finds angles from trigonometric ratios using the inverse functions arcsin, arccos, and arctan.
- Choose a function. Select arcsin, arccos, or arctan from the dropdown. Each function accepts different input ranges.
- Enter a value. For arcsin and arccos, the value must be between -1 and 1. Arctan accepts any real number.
- Read the result. The angle is displayed in both degrees and radians. Results update instantly as you type.
Use the Share button to generate a link with your current inputs, or Copy to grab the result text.
About Inverse Trigonometric Functions
Inverse trig functions reverse the standard trig functions. Where sin takes an angle and returns a ratio, arcsin takes a ratio and returns an angle. Arcsin (sin inverse) has a domain of [-1, 1] and returns angles from -90 to 90 degrees. Arccos has the same domain but returns angles from 0 to 180 degrees. Arctan accepts any real number and returns angles from -90 to 90 degrees. These functions are essential for finding unknown angles in trigonometry, physics, and engineering problems.
Frequently Asked Questions
Why does arcsin only accept values between -1 and 1?
The sine function only outputs values between -1 and 1 for any angle. Since arcsin reverses the sine function, its input must be within that same range. If you enter a value outside [-1, 1], no real angle has that sine value, so the result is undefined.
What is the difference between arcsin and sin inverse?
They are the same thing. Arcsin, sin inverse, sin^(-1), and asin all refer to the inverse sine function. The notation varies by textbook and calculator, but the calculation is identical.
Why does arctan accept any number?
Unlike sine and cosine, the tangent function can produce any real number as output. As an angle approaches 90 degrees, tangent approaches infinity. Because tangent covers all real numbers, its inverse (arctan) accepts any real number as input and returns an angle between -90 and 90 degrees.