Inverse Trigonometric Functions Calculator

Find angles with arcsin, arccos, arctan, arccsc, arcsec, and arccot, with precise answers in radians and degrees.

Calculate an inverse trigonometric function
Choose a function and enter its trigonometric ratio to recover the principal angle.

About inverse trigonometric functions

Inverse trigonometric functions recover an angle from a known trigonometric ratio. Ordinary sine, cosine, and tangent start with an angle and produce a number. Their inverse functions reverse that direction: arcsine starts with a sine ratio, arccosine starts with a cosine ratio, and arctangent starts with a tangent ratio. These operations are essential when a right triangle provides side lengths but the missing quantity is an angle. They also appear throughout navigation, surveying, physics, computer graphics, signal processing, and engineering. Each inverse function returns a principal value because infinitely many angles can share the same trigonometric ratio. Arcsine returns an angle from negative pi over two through positive pi over two. Arccosine returns an angle from zero through pi. Arctangent returns an angle strictly between negative pi over two and positive pi over two. This calculator uses those standard principal branches. Arccotangent is defined here with a principal range from zero through pi, using the two-argument arctangent convention so negative inputs produce an angle in the second quadrant. The reciprocal functions follow directly from the primary functions. Arccosecant of a value is arcsine of its reciprocal, while arcsecant is arccosine of its reciprocal. Consequently, arcsine and arccosine accept values from negative one through one. Arccosecant and arcsecant accept values whose absolute magnitude is at least one. Arctangent and arccotangent accept every finite real number. Domain checking matters because values outside these ranges do not correspond to real angles. Results are displayed in both radians and degrees. Radians are the natural unit for calculus and most programming libraries because they measure an angle through arc length. Degrees divide a complete turn into 360 familiar units and are often easier to interpret in geometry or practical measurement. The conversion is degrees equals radians multiplied by 180 and divided by pi. Keeping both forms visible prevents unit confusion and makes the answer useful in either classroom or technical work. To interpret a result, remember that the calculator returns one representative angle, not every coterminal or periodic solution. For an equation involving sine, cosine, or tangent, additional solutions may be found from symmetry and the function's period. Use the principal result as the starting point, then apply the relevant identities for the interval in your problem. The calculator preserves enough decimal precision for common mathematical and engineering work while presenting a readable rounded value.

Inverse trigonometric examples

CalculationPrincipal resultInterpretation
arcsin(0.5)0.5235987756 rad or 30°The sine of 30 degrees is one half.
arccos(0)1.5707963268 rad or 90°The cosine of a right angle is zero.
arctan(1)0.7853981634 rad or 45°Equal opposite and adjacent sides form a 45 degree angle.
arcsec(2)1.0471975512 rad or 60°A secant ratio of two corresponds to cosine one half.

How to use the calculator

  1. Choose the inverse trigonometric function that matches the known ratio.
  2. Enter the ratio as a decimal or whole number in the Value field.
  3. Select Calculate angles to check the domain and compute the principal angle.
  4. Read the equivalent result in radians and degrees.

Inverse trigonometric functions FAQ

What is an inverse trigonometric function?

It is a function that recovers a principal angle from a trigonometric ratio. For example, arcsine of one half is 30 degrees because sine of 30 degrees equals one half.

Are arcsin and one divided by sine the same?

No. Arcsin is the inverse function of sine, while one divided by sine is cosecant. The notation can look similar, so the context and the arc prefix are important.

Why can arcsin only accept values from negative one to one?

The sine of a real angle never falls below negative one or rises above one. A value outside that interval therefore has no real arcsine result.

Why does the calculator show radians and degrees?

Radians are standard in calculus, physics, and software, while degrees are common in geometry and everyday measurement. Showing both makes the same principal angle immediately useful in either convention.

Does the result include every possible angle?

No. An inverse trigonometric function returns the principal value from a defined range. Periodic equations may have additional solutions that must be found using symmetry and full-turn periods.