7

Solving Equations

In chapter 6 you saw how you can use što find the value of the left–hand variable in an assignment–type equation. Well, you can use SOLVE to find the value of any variable in any type of equation.

For example, consider the equation

x2 – 3y = 10

If you know the value of y in this equation, then SOLVE can solve for the unknown x. If you know the value of x, then SOLVE can solve for the unknown y. This works for "word problems" just as well:

Markup Cost = Price

If you know any two of these variables, then SOLVE can calculate the value of the third.

When the equation has only one variable, or when known values are supplied for all variables except one, then to solve for x is to find a root of the equation. A root of an equation occurs where an equality or assignment equation balances exactly, or where an expression equation equals zero. (This is equivalent to the value of the equation being zero.)

Solving an EquationTo solve an equation for an unknown variable:

1.Press {Gand display the desired equation. If necessary, type the equation as explained in chapter under "Entering Equations into the Equation List."

2.Press { œ then press the key for the unknown variable. For example, press X to solve for x. The equation then prompts

Solving Equations 7–1

File name 32sii-Manual-E-0424

 

Printed Date : 2003/4/24

Size : 17.7 x 25.2 cm