Enter a value x into the calculator. The calculator will evaluate and display the inverse cosine of the angle using the arccosine formula.

Inverse Cosine Formula

The following formula can calculate an angle from any cosine value.

Arccosine(x) = C
Cosine C = x
  • Where AC is arc cosine, which is the same as saving inverse cosine
  • x is a cosine value of two sides of a triangle.

Inverse Cosine Definition

Inverse cosine, or arc cosine or acos, is a mathematical function that takes a value between -1 and 1 as input and returns an angle in radians between 0 and π (pi) as output. It is the opposite operation of the cosine function.

Inverse cosine is important because it allows us to find the angle whose cosine equals a given value. This concept is particularly useful in trigonometry and geometry, where we often must determine angles based on known cosine values. Inverse cosine helps solve various real-life problems, such as calculating distances, angles of elevation or depression, and determining the unknown side lengths or angles of triangles.

It also plays a significant role in physics, engineering, and computer graphics. By using inverse cosine, we can accurately determine angles and make precise calculations, contributing to the understanding and applying mathematical principles in various domains.

Inverse Cosine Example

How to calculate inverse cosine.

  1. First, find the ratio of the adjacent side to the opposite side.

    These are the sides of the angle.

  2. Next, calculate the angle.

    Calculate the angle using the inverse cosine.


What is the inverse cosine?

The inverse cosine is also known as the arc cosine and is used to calculate the value of an angle when the cosine of that angle is known.

What is arc cosine?

Arc cosine is just another way of saying the inverse cosine. The formula is the same as the inverse cosine.

inverse cosine calculator
inverse cosine formula