hp40g+.book Page 37 Friday, December 9, 2005 1:03 AM

then press ENTER. The following is then written to the Equation Writer:

 

⎛x = –--1⎞

AND ⎛y = --5⎞

AND ⎛z = –--1⎞

 

⎝

2⎠

⎝

2⎠

⎝

2⎠

SOLVE

Solve equations

 

 

 

 

SOLVE has as two parameters:

 

(1) either an equality between two expressions, or a single expression (in which case = 0 is implied), and

(2) the name of a variable.

SOLVE solves the equation in R in real mode and in C in complex mode (ignoring REALASSUME).

Typing:

SOLVE(X4-1=3,X)

gives, in real mode:

(x = −√2) OR (x = √2) or, in complex mode:

(x = −√2) OR (x = √2) OR (x = −i · √2) OR (x = i√2)

Solve systems

SOLVE also enables you to solve a system of non-linear equations, if they are polynomials. (If they are not polynomials, use MSOLV in the HOME screen to get a numerical solution.)

It is assumed that the various equations are of the form expression = 0.

SOLVE has as arguments, the first members of the various equations separated by AND, and the names of the various variables separated by AND.

Typing:

SOLVE(X2+Y2-3 AND X-Y2+1,X AND Y) gives:

(x = 1) AND (y = −√2) OR (x = 1) AND (y = √2)

Computer Algebra System (CAS)

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