Difference between revisions of "TrigExpand Command"

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;TrigExpand( <Expression> )
 
;TrigExpand( <Expression> )
 
:Transforms a trigonometric expression into an expression using only simple variables as arguments.
 
:Transforms a trigonometric expression into an expression using only simple variables as arguments.
:{{example|1=<code>TrigExpand[tan(x + y)]</code> gives <math>\frac{\frac{sin(x)}{cos(x)}+\frac{sin(y)}{cos(y)}} {1-\frac{sin(x)}{cos(x)} \cdot \frac{sin(y)}{cos(y)}} </math>.}}
+
:{{example|1=<code>TrigExpand(tan(x + y))</code> gives <math>\frac{\frac{sin(x)}{cos(x)}+\frac{sin(y)}{cos(y)}} {1-\frac{sin(x)}{cos(x)} \cdot \frac{sin(y)}{cos(y)}} </math>.}}
  
 
;TrigExpand( <Expression>, <Target Function> )
 
;TrigExpand( <Expression>, <Target Function> )
 
:Transforms a trigonometric expression into an expression using only simple variables as arguments, preferring the given target function.
 
:Transforms a trigonometric expression into an expression using only simple variables as arguments, preferring the given target function.
:{{example|1=<code>TrigExpand[tan(x + y), tan(x)]</code> gives <math>\frac{-tan(x) - tan(y)}{tan(x) tan(y) - 1}</math>.}}
+
:{{example|1=<code>TrigExpand(tan(x + y), tan(x))</code> gives <math>\frac{-tan(x) - tan(y)}{tan(x) tan(y) - 1}</math>.}}
  
 
==CAS Syntax==
 
==CAS Syntax==
 
CAS syntaxes may show different results, depending on the selected output mode:  
 
CAS syntaxes may show different results, depending on the selected output mode:  
  
:{{example|1=<code>TrigExpand[tan(x + y)]</code> <br/> in [[Image:Mode evaluate.svg|32px]] ''Evaluate'' mode  gives  <math>\frac{\frac{sin(x)}{cos(x)}+\frac{sin(y)}{cos(y)}} {1-\frac{sin(x)}{cos(x)} \cdot \frac{sin(y)}{cos(y)}} </math> <br/> in [[Image:Mode numeric.svg|32px]] ''Numeric'' mode  gives  <math>\frac{sin(x) cos(y) + sin(y) cos(x)}{- sin(x) sin(y) +cos(x) cos(y) }</math> .}}
+
:{{example|1=<code>TrigExpand(tan(x + y))</code> <br/> in [[Image:Mode evaluate.svg|32px]] ''Evaluate'' mode  gives  <math>\frac{\frac{sin(x)}{cos(x)}+\frac{sin(y)}{cos(y)}} {1-\frac{sin(x)}{cos(x)} \cdot \frac{sin(y)}{cos(y)}} </math> <br/> in [[Image:Mode numeric.svg|32px]] ''Numeric'' mode  gives  <math>\frac{sin(x) cos(y) + sin(y) cos(x)}{- sin(x) sin(y) +cos(x) cos(y) }</math> .}}
  
  
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;TrigExpand( <Expression>, <Target Function>, <Target Variable> )
 
;TrigExpand( <Expression>, <Target Function>, <Target Variable> )
 
:Transforms a trigonometric expression into an expression using only simple variables as arguments, preferring the given target function and target variable.
 
:Transforms a trigonometric expression into an expression using only simple variables as arguments, preferring the given target function and target variable.
:{{example|1=<code>TrigExpand[sin(x), sin(x), x/2]</code> gives <math>2cos \left( \frac{x}{2} \right) sin \left( \frac{x}{2} \right) </math>.}}
+
:{{examples|1=<div>
:{{example|1=<code>TrigExpand[sin(x)/(1+cos(x)), tan(x), x/2]</code> gives <math>tan \left( \frac{x}{2} \right)</math>.}}
+
:*<code>TrigExpand(sin(x), sin(x), x/2)</code> gives <math>2cos \left( \frac{x}{2} \right) sin \left( \frac{x}{2} \right) </math>
 +
:*<code>TrigExpand(sin(x)/(1+cos(x)), tan(x), x/2)</code> gives <math>tan \left( \frac{x}{2} \right)</math>.</div>}}
  
  
 
;TrigExpand( <Expression>, <Target Function>, <Target Variable>, <Target Variable> )
 
;TrigExpand( <Expression>, <Target Function>, <Target Variable>, <Target Variable> )
 
:Transforms a trigonometric expression into an expression using only simple variables as arguments, preferring the given target function and target variables.
 
:Transforms a trigonometric expression into an expression using only simple variables as arguments, preferring the given target function and target variables.
:{{example|1=<code>TrigExpand[csc(x) - cot(x) + csc(y) - cot(y), tan(x), x/2, y/2]</code> gives <math>tan \left( \frac{x}{2} \right) +tan \left( \frac{y}{2} \right) </math>.}}
+
:{{example|1=<code>TrigExpand(csc(x) - cot(x) + csc(y) - cot(y), tan(x), x/2, y/2)</code> gives <math>tan \left( \frac{x}{2} \right) +tan \left( \frac{y}{2} \right) </math>.}}
  
 
{{note|See also [[TrigSimplify Command]] and [[TrigCombine Command]].}}
 
{{note|See also [[TrigSimplify Command]] and [[TrigCombine Command]].}}

Revision as of 10:01, 9 October 2017


TrigExpand( <Expression> )
Transforms a trigonometric expression into an expression using only simple variables as arguments.
Example: TrigExpand(tan(x + y)) gives \frac{\frac{sin(x)}{cos(x)}+\frac{sin(y)}{cos(y)}} {1-\frac{sin(x)}{cos(x)} \cdot \frac{sin(y)}{cos(y)}} .


TrigExpand( <Expression>, <Target Function> )
Transforms a trigonometric expression into an expression using only simple variables as arguments, preferring the given target function.
Example: TrigExpand(tan(x + y), tan(x)) gives \frac{-tan(x) - tan(y)}{tan(x) tan(y) - 1}.


CAS Syntax

CAS syntaxes may show different results, depending on the selected output mode:

Example: TrigExpand(tan(x + y))
in Mode evaluate.svg Evaluate mode gives \frac{\frac{sin(x)}{cos(x)}+\frac{sin(y)}{cos(y)}} {1-\frac{sin(x)}{cos(x)} \cdot \frac{sin(y)}{cos(y)}}
in Mode numeric.svg Numeric mode gives \frac{sin(x) cos(y) + sin(y) cos(x)}{- sin(x) sin(y) +cos(x) cos(y) } .


The following commands are only available in the Menu view cas.svg CAS View:

TrigExpand( <Expression>, <Target Function>, <Target Variable> )
Transforms a trigonometric expression into an expression using only simple variables as arguments, preferring the given target function and target variable.
Examples:
  • TrigExpand(sin(x), sin(x), x/2) gives 2cos \left( \frac{x}{2} \right) sin \left( \frac{x}{2} \right)
  • TrigExpand(sin(x)/(1+cos(x)), tan(x), x/2) gives tan \left( \frac{x}{2} \right).


TrigExpand( <Expression>, <Target Function>, <Target Variable>, <Target Variable> )
Transforms a trigonometric expression into an expression using only simple variables as arguments, preferring the given target function and target variables.
Example: TrigExpand(csc(x) - cot(x) + csc(y) - cot(y), tan(x), x/2, y/2) gives tan \left( \frac{x}{2} \right) +tan \left( \frac{y}{2} \right) .


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