# TrigExpand Command

##### Command Categories (All commands)

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

TrigExpand[ <Expression> ]
Transforms a trigonometric expression into an expression using only simple variables as arguments.
Example: TrigExpand[tan(x + y)] gives \frac{cos(x) sin(y) + cos(y) sin(x)}{cos(x) cos(y) - sin(x) sin(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}.
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 tagret variable.
Example: TrigExpand[sin(x), sin(x), x/2] gives 2cos(\frac{x}{2})sin(\frac{x}{2}).
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(\frac{x}{2})+tan(\frac{y}{2}).
• GeoGebra
• Help
• Partners