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Template:Acos/doc
From OeisWiki
The {{acos}} circular function template returns the arc cosine (a circular angle in radians) of , where is a real number in closed interval [-1, +1].
Note that you may also use the acos operator (used within the {{#expr: }} parser function extension, e.g. {{#expr: acos 0.5 }}) which also returns a circular angle in radians.
Contents
Usage
- {{acos|a real number in closed interval [-1, +1]}}
Valid input
- A real number in closed interval [-1, +1].
Examples
Examples with valid input
Code Result {{acos|- (2^(1/2) / 2)}} 2.3561944901923 {{acos|-0.5}} 2.0943951023932 {{acos|0}} 1.5707963267949 {{acos|0.5}} 1.0471975511966 {{acos|2^(1/2) / 2}} 0.78539816339745
Examples with invalid input (returns an error message)
Code Result {{acos|i}} Expression error: Unrecognized word "i". {{acos|- (2^(1/2))}} Invalid argument for acos: < -1 or > 1. {{acos|+ 2^(1/2)}} Invalid argument for acos: < -1 or > 1.
Code
Currently (using built-in error message)
{{#expr: acos ({{{1}}}) }}
instead of (using custom error message)
{{ifnum| {{{1|NAN}}} | {{#ifexpr: abs ({{{1}}}) <= 1 | {{#expr: acos ({{{1}}}) }} | {{error| Acos error: Argument must be a real number in closed interval [-1, +1] }} }} | {{error| Acos error: Argument must be a real number in closed interval [-1, +1] }} }}
See also