Arccos(x) calculator. Inverse cosine calculator.

Enter value of x (between -1 and 1) and hit "Calculate" button

Arccos(x), cos^{-1}(x), inverse cosine function.

## Arccos definition

The arccosine of x is defined as the inverse cosine function of x when -1≤x≤1.

When the cosine of y is equal to x:

cos *y* = *x*

Then the arccosine of x is equal to the inverse cosine function of x, which is equal to y:

arccos *x* = cos^{-1}* x* = *y*

(Here cos^{-1} x means the inverse cosine and does not mean cosine to the power of -1).

#### Example

arccos 1 = cos^{-1} 1 = 0 rad = 0°

## Graph of arccos

## Arccos rules

Rule name | Rule |
---|---|

Cosine of arccosine | cos( arccos x ) = x |

Arccosine of cosine | arccos( cos x ) = x + 2kπ, when k∈ℤ (k is integer) |

Arccos of negative argument | arccos(-x) = π - arccos x = 180° - arccos x |

Complementary angles | arccos x = π/2 - arcsin x = 90° - arcsin x |

Arccos sum | arccos(α) + arccos(β) =arccos( αβ - √(1-α^{2})(1-β^{2}) ) |

Arccos difference | arccos(α) - arccos(β) =arccos( αβ + √(1-α^{2})(1-β^{2}) ) |

Arccos of sin of x | arccos( sin x ) = -x - (2k+0.5)π |

Sine of arccosine | |

Tangent of arccosine | |

Derivative of arccosine | |

Indefinite integral of arccosine |

## Arccos table

x | arccos(x) (rad) | arccos(x) (°) |
---|---|---|

-1 | π | 180° |

-√3/2 | 5π/6 | 150° |

-√2/2 | 3π/4 | 135° |

-1/2 | 2π/3 | 120° |

0 | π/2 | 90° |

1/2 | π/3 | 60° |

√2/2 | π/4 | 45° |

√3/2 | π/6 | 30° |

1 | 0 | 0° |

Currently, we have around 1975 calculators, conversion tables and usefull online tools and software features for students, teaching and teachers, designers and simply for everyone.

You can find at this page financial calculators, mortgage calculators, calculators for loans, calculators for auto loan and lease calculators, interest calculators, payment calculators, retirement calculators, amortization calculators, investment calculators, inflation calculators, finance calculators, income tax calculators, compound interest calculators, salary calculator, interest rate calculator, sales tax calculator, fitness & health calculators, bmi calculator, calorie calculators, body fat calculator, bmr calculator, ideal weight calculator, pace calculator, pregnancy calculator, pregnancy conception calculator, due date calculator, math calculators, scientific calculator, fraction calculator, percentage calculators, random number generator, triangle calculator, standard deviation calculator, other calculators, age calculator, date calculator, time calculator, hours calculator, gpa calculator, grade calculator, concrete calculator, subnet calculator, password generator conversion calculator and many other tools and for text editing and formating, downloading videos from Facebok (we built one of the most famous Facebook video downloader online tools). We also provide you online downloanders for YouTube, Linkedin, Instagram, Twitter, Snapchat, TikTok and other social media sites (please note we does not host any videos on its servers. All videos that you download are downloaded from Facebook's, YouTube's, Linkedin's, Instagram's, Twitter's, Snapchat's, TikTok's CDNs. We also specialise on keyboard shortcuts, ALT codes for Mac, Windows and Linux and other usefull hints and tools (how to write emoji online etc.)

There are many very usefull online free tools and we would be happy if you share our page to others or send us any suggestions for other tools which will come on your mind. Also in case you find any of our tools that it does not work properly or need a better translation - please let us know. Our tools will make your life easier or simply help you to do your work or duties faster and in more effective way.

These below are the most commonly used by many users all over the world.

- Free online calculators and tools
- Free online units conversion tools
- Free online web design tools
- Free online electricity & electronics tools
- Mathematics
- Online Tools
- Text Tools
- PDF Tools
- Code
- Ecology
- Others
- Free online electrical calculators and tools
- Free online financial calculators and tools
- Free online grade calculators and tools
- Free online lighting calculators and tools
- Free online math calculators and tools
- Free online wire calculators and tools
- Free online time calculators and tools
- Free online baby calculators and tools
- Free online body calculators and tools
- Adding fractions free online calculator
- Addition free online calculator
- Antilog free online calculator
- Arccos free online calculator
- Arcsin free online calculator
- Arctan free online calculator
- Average free online calculator
- Base free online calculator
- Binary free online calculator
- Convolution free online calculator
- Cosine free online calculator
- Dividing fractions free online calculator
- Division free online calculator
- Exponential growth/decay formula calculator online free
- Exponents free online calculator
- Factorial free online calculator
- Fractions free online calculator
- Greatest common factor free online calculator
- Least common multiple free online calculator
- Logarithm free online calculator
- Math free online calculator
- Multiplication free online calculator
- Multiplying fractions free online calculator
- Natural logarithm free online calculator
- Percent error free online calculator
- Percentage change free online calculator
- Percentage free online calculator
- Percentage increase/decrease free online calculator
- Pythagorean theorem free online calculator
- Quadratic equation free online calculator
- Radicals and roots free online calculator
- Random number free online generator
- Random number generator 0-1
- Random number generator 0-10
- Random number generator 0-100
- Random number generator 0-9
- Random number generator 0-99
- Random number generator 1-10
- Random number generator 1-100
- Random number generator 1-2
- Random number generator 1-20
- Random number generator 1-3
- Random number generator 1-4
- Random number generator 1-5
- Random number generator 1-6
- Ratio free online calculator
- Scientific notation free online calculator
- Simplifying fractions free online calculator
- Sine free online calculator
- Square root free online calculator
- Standard deviation free online calculator
- Subtracting fractions free online calculator
- Subtraction free online calculator
- Tangent free online calculator
- Trigonometry free online calculator
- Variance free online calculator
- Weighted average free online calculator

And we are still developing more. Our goal is to become the one-stop, go-to site for people who need to make quick calculations or who need to find quick answer for basic conversions.

Additionally, we believe the internet should be a source of free information. Therefore, all of our tools and services are completely free, with no registration required. We coded and developed each calculator individually and put each one through strict, comprehensive testing. However, please inform us if you notice even the slightest error – your input is extremely valuable to us. While most calculators on Justfreetools.com are designed to be universally applicable for worldwide usage, some are for specific countries only.