THE NUMORIX GUIDE
How to use the Trigonometry Calculator
Last reviewed September 14, 2026
What this calculator does
For sin, cos, and tan, convert a degree input to radians when needed and evaluate the function.
Formula and method
For sin, cos, and tan, convert a degree input to radians when needed and evaluate the function. For asin, acos, and atan, the engine evaluates the inverse function and reports both its radian and degree result.
Variables and inputs
Operation defaults to sin, angle defaults to 30, and unit defaults to degrees. Operations include sin, cos, tan, asin, acos, and atan; inverse inputs should be dimensionless values in the appropriate domain.
Worked example
Default sin(30 degrees): radians = 30*pi/180 = 0.523599; sin(0.523599) = 0.5; reported degree conversion of the result is 28.6479 degrees because the result itself is a ratio converted as an angle by the engine.
How to interpret the result
For forward functions, the result is a ratio (with tan potentially unbounded); inverse functions return an angle. The engine's result field is formatted as a degree conversion for every operation.
Common mistakes to avoid
Do not mix degrees and radians. For asin and acos, enter a value from -1 to 1 rather than an angle; for tan, avoid angles near 90 degrees where the value becomes very large.
Assumptions and limitations
The current inverse-function path still applies the selected unit conversion before asin/acos/atan and always converts the result to degrees, so inverse-mode output should be independently verified. It does not handle complex values.
Practical use and checks
The Trigonometry Calculator supports the basic sine, cosine, and tangent functions plus inverse operations, with an explicit degrees or radians choice. As a direct check, choose sine, enter 30 degrees, and verify the mathematical trig value is 0.5; choose cosine at 60 degrees for the same 0.5 check. For tangent at 45 degrees, the value should be 1. In a right triangle, use the ratio that matches the known sides before selecting an inverse function to recover an angle. Angle units are the most common source of error. A 30-degree angle is pi/6 radians, while entering 30 in a radians field means a completely different angle. Inverse sine and cosine accept a real ratio from -1 through 1 and return a principal angle, so they do not identify every possible angle with that same ratio; the unit selector controls the unit of the returned angle for inverse operations, while the input is the ratio itself. Tangent becomes unstable or undefined near 90 degrees plus integer multiples of 180 degrees. Do not use a rounded trig value as a precision measurement without retaining the original angle and unit.