The cos trigonometric function calculates the cos of an angle in radians, degrees or gradians.

The calculator allows to use most of the **trigonometric functions**, it is possible to calculate the
**cosine**,
the sine
and the tangent
of an angle through the functions of the same name..

The **trigonometric function cosine** noted **cos**,
allows to **calculate
the cosine of an angle online **, it is possible to use different angular units :
degrees, gradians and radians wich is the angular unit by default.

- Calculation of the cosine
- Special cosine values
- Main properties
- `cos(-x)= cos(x)`
- `cos(x+2*k*pi)=cos(x)`
- `cos(pi-x)=-cos(x)`
- `cos(pi+x)=-cos(x)`
- `cos(pi/2-x)=sin(x)`
- `cos(pi/2+x)=-sin(x)`
- Derivative of cosine
- Antiderivative of cosine
- Properties of the cosine function
- Equation with cosine

The **cosine calculator** allows through the cos function to **calculate**
**online** the **cosine** of an angle in radians, you must first
select the desired unit by clicking on the options button calculation module.
After that, you can start your calculations.

To **calculate cosine online** of `pi/6`, enter
cos(`pi/6`), after calculation, the result
`sqrt(3)/2` is returned.

Note that the cosine function is able to recognize some special angles and make the calculations with special associated values in exact form.

To **calculate the cosine of an angle** in degrees, you must first select the desired unit
by clicking on the options button calculation module. After that, you can start your calculus.

To calculate cosine of 90, enter cos(90), after calculation, the restults 0 is returned.

To calculate the cosine of an angle in gradians, you must first select the desired unit by clicking on the options button calculation module. After that, you can start your calculus.

To calculate cosine of 50, enter cos(50), after computation, the result `sqrt(2)/2` is returned.

Note that the cosine function is able to recognize some special angles and do the calculus with special associated exact values.

The cosine admits some special values which the calculator is able to determine in exact forms. Here is the list of
the **special cosine values**:

cos(`2*pi`) | `1` |

cos(`pi`) | `-1` |

cos(`pi/2`) | `0` |

cos(`pi/4`) | `sqrt(2)/2` |

cos(`pi/3`) | `1/2` |

cos(`pi/6`) | `sqrt(3)/2` |

cos(`2*pi/3`) | `-1/2` |

cos(`3*pi/4`) | `-sqrt(2)/2` |

cos(`5*pi/6`) | `-sqrt(3)/2` |

cos(`0`) | `1` |

cos(`-2*pi`) | `1` |

cos(`-pi`) | `-1` |

cos(`pi/2`) | `0` |

cos(`-pi/4`) | `sqrt(2)/2` |

cos(`-pi/3`) | `1/2` |

cos(`-pi/6`) | `sqrt(3)/2` |

cos(`-2*pi/3`) | `-1/2` |

cos(`-3*pi/4`) | `-sqrt(2)/2` |

cos(`-5*pi/6`) | `-sqrt(3)/2` |

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The derivative of the cosine is equal to -sin(x).

The antiderivative of the cosine is equal to sin(x).

The **cosine** function is an even function, for every real x, `cos(-x)=cos(x)`.
The consequence for the curve representative of the cosine function is that it admits the axis of the ordinates as axis of symmetry.

The calculator has a solver which allows it to solve
equation with cosine
of the form **cos(x)=a**.
The calculations to obtain the result are detailed, so it will be possible to solve equations like
`cos(x)=1/2`
or
`2*cos(x)=sqrt(2)`
with the calculation steps.

cos(x), where x is the measure of an angle in degrees, radians, or gradians.

cos(`0`), returns 1

To differentiate function cosine online, it is possible to use the derivative calculator which allows the calculation of the derivative of the cosine function

The **derivative of cos(x)** is derivative(`cos(x)`)=`-sin(x)`

Antiderivative calculator allows to calculate an antiderivative of cosine function.

An **antiderivative of cos(x)** is antiderivative(`cos(x)`)=`sin(x)`

The limit calculator allows the calculation of limits of the cosine function.

The **limit of cos(x)** is limit(`cos(x)`)

The **inverse function of cosine** is the arccosine function noted arccos.

The graphing calculator is able to plot cosine function in its definition interval.

See also

- Arccosine : arccos. The arccos function allows the calculation of the arc cosine of a number. The arccos function is the inverse functions of the cosine function.
- Arcsine : arcsin. The arcsin function allows the calculation of the arc sine of a number. The arcsin function is the inverse function of the sine function.
- Arctangent : arctan. The arctan function allows the calculation of the arctan of a number. The arctan function is the inverse functions of the tangent function.
- Trigonometric Calculator : simplify_trig. Calculator wich uses trigonometric formula to simplify trigonometric expression.
- Cosine : cos. The cos trigonometric function calculates the cos of an angle in radians, degrees or gradians.
- Cosecant : cosec. The trigonometric function sec allows to calculate the secant of an angle expressed in radians, degrees, or grades.
- Cotangent : cotan. The cotan trigonometric function to calculate the cotan of an angle in radians, degrees or gradians.
- Trigonometric expansion : expand_trigo. The calculator makes it possible to obtain the trigonometric expansion of an expression.
- Trigonometric linearization : linearization_trigo. Calculator that allows to linearize a trigonometric expression.
- Simplify Calculator : simplify. Calculator wich can simplify an algebraic expression online.
- Secant : sec. The trigonometric function sec allows to calculate the secant of an angle expressed in radians, degrees, or grades.
- Sine : sin. The sin trigonometric function to calculate the sin of an angle in radians, degrees or gradians.
- Tangent : tan. The tan trigonometric function to calculate the tan of an angle in radians, degrees or gradians.