CAS Equation Writer

The HP 40g Equation Writer enables you to type expressions that you want to simplify, factor, differentiate, integrate, and so on, and then work them through as if on paper. The {CAS} key on the home menu bar takes you into the Equation Writer, and the [HOME] key takes you back out to the HP 40gs Home View Screen. The Equation Writer is a very efficient editor for writing, simplifying and transforming mathematical expressions. When you type expressions in the Equation Writer, the operator that you are typing always carries over to the adjacent or selected expression.

40g Equation Writer

The Equation Writer is supplied with a menu bar of menus:

TOOL menu contains the commands:

ALGB menu contains functions that enable you to perform algebra: factoring, expansion, simplification, substitution.

COLLECT, DEF, EXPAND, FACTOR, PARTFRAC, QUOTE, STORE, | , SUBST, TEXPAND, UNASSIGN.

DIFF menu contains functions that enable you to perform differential calculus: differentiation, integration, series expansion, limits.

DERIV, DERVX, DIVPC, FOURIER, IBP, INTVX, LIMIT, PREVAL, RISCH, SERIES, TABVAR, TAYLOR0, TRUNC.

REWRI menu contains functions that enable you to rewrite an expression in another form.

DISTRIB, EPSX0, EXPLN, EXP2POW, FDISTRIB, LIN, LNCOLLECT, POWEXPAND, SINCOS, SIMPLIFY, XNUM, XQ.

SOLV menu contains functions that enable you to solve equations, linear systems, and differential equations.

DESOLVE, ISOLATE, LDEC, LINSOLVE, SOLVE, SOLVEX.

TRIG menu contains functions that enable you to transform trigonometric expressions.

ACOS2S, ASIN2C, ASIN2T, ATAN2S, HALFTAN, SINCOS, TAN2CS2, TAN2SC, TAN2SC2, TCOLLECT, TEXPAND, TLIN, TRIG, TRIGCOS, TRIGSIN, TRIGTAN.