# Arc Cosine (acos) Calculator

### Arc Cosine (acos) Calculator

Calculated acos() of the number

### acos() function

Arc Cosine (acos) is the inverse function of Cosine (cos), which means that a==cos(acos(a)) for every value of a that is within acos()'s range.

This is an online free acos calculator. You can calculate value of acos() trignometric function easily using this tool.

### Important Abbreviations to remember

• SOH: Opposite / Hypotenuse (Sine)
• CAH: Adjacent / Hypotenuse (Cosine)
• TOA: Opposite / Adjacent (Tangent)

### Understanding the Main Trigonometric Functions

In mathematics, the trigonometric functions (also called circular functions, angle functions or goniometric functions) are functions of an angle. They relate the angles of a triangle to the lengths of its sides. Degrees and Radians are units of measuring these angles. Degrees originated as an unit to measure how far constellations moved in a day (1 degree ~ 1 day of movement). Degrees measure angles by how far we tilted our heads(Observer's view point). Radians measure angles by distance traveled(Movers's view point).