CASTI-89 TITANIUM · CALC89
tExpand(
Expands sines and cosines of sums and multiple angles into products of sines and cosines of single angles. Use it to check double angle and angle sum formulas.
Syntax
tExpand(expr)
- Group
- Algebra
- Arguments
- Takes one trigonometric expression.
- Availability
- Pro feature in Calc89
- Menu path
- F2 Algebra ▸ Trig ▸ tExpand(
Example
| Input | Result |
|---|---|
| tExpand(sin(2x)) | 2·sin(x)·cos(x) |
Typing tExpand(sin(2x)) on the home screen and pressing ENTER returns 2·sin(x)·cos(x).
Keystrokes on the TI-89 Titanium
F2▶1
The same key sequence inserts tExpand( in Calc89, and the AI tutor shows it step by step on the on-screen keypad.
Related commands
- when(Returns one of several values depending on whether a condition is true, false or undecided.
- zeros(Returns the real values of the variable that make an expression zero, as a list.
- approx(Evaluates an expression numerically and returns a decimal approximation, even when the calculator is in exact mode.
- cFactor(Factors an expression over the complex numbers, so factors with non-real coefficients such as x+ⅈ are allowed.
- comDenom(Combines a sum of fractions into one reduced fraction over a common denominator.
- completeSquare(Rewrites a quadratic expression in completed square form.
- cPolyRoots(Returns all roots of a polynomial as a list, including non-real complex roots.
- cSolve(Solves an equation over the complex numbers and returns both real and non-real solutions.