arccos

Inverse cosine function

Arccos is the inverse cosine function in trigonometry, also written as cos⁻¹.

Given a value between -1 and 1, arccos returns the angle whose cosine equals that value.

The result is typically expressed in radians (between 0 and π) or degrees (between 0° and 180°).

The arccos of 0.5 is 60 degrees.

It appears frequently in mathematics, physics, and programming contexts where you need to work backward from a cosine value to find an angle.

function

principal value

Canonical multivalued function output

domainArea of control
rangeExtent of variation
unit circleRadius-one circle at origin

quadrant · radians · degrees · graph · monotonic · output · input · evaluation · computation · notation

trigonometry

adjacent

Directly next to

hypotenuseLongest right-triangle side
ratioComparative numerical relation
triangleThree-sided plane figure

sine · tangent · secant · cosecant · cotangent · unit circle · periodic · angle · identity · complementary

application

physics

Science of matter and energy

engineeringDesigning functional systems scientifically
rotationTurning on an axis
dot productSum of component products

navigation · robotics · computer graphics · 3D modeling · animation · signal processing

Categories

trigonometrysine, tangent, secant, cosecant, cotangent
inverse functionsarcsin, arctan, arcsine, arccosine, arctangent
math functionssine, abs, add, tangent, subtract

Opposites

inverse vs direct function

arccoscos

Trig ratio abbreviation

trigonometric function type

arccosarcsin

Inverse of sine

arcsine · arctan · arctangent · inverse sine · arccot

Family

Familiarity: Top 1,000,000
Profile: Used worldwide · Timeless · Abstract · Rated G