EL-9900 Graphing Calculator

Solving a Literal Equation Using Newton's Method(Area of a Trapezoid)

The Solver mode is used to solve one unknown variable by inputting known variables. There are three methods: Equation, Newton’s, and Graphic. The Newton’s method can be used for more complicated equations. This method implements an iterative approach to find the solution once a starting point is given.

Example

Find the height of a trapezoid from the formula for calculating the area of a trapezoid using Newton’s method.

The formula : A=

1

h(b+c)

(A = area h = height b = top face c = bottom face)

2

 

 

 

1. Find the height of a trapezoid with an area of 25in2 and bases of length 5in and 7in using Newton's method. (Set the starting point to 1.)

2. Save the formula as “A TRAP”.

3. Find the height of a trapezoid with an area of 50in2 with bases of 8in and 10in using the saved formula. (Set the starting point to 1.)

Before

Starting

There may be differences in the results of calculations and graph plotting depending on the setting. Return all settings to the default value and delete all data.

As the Solver feature is only available on the Advanced keyboard, this section does not apply to the Basic keyboard.

Step & Key Operation

Display

Notes

1-1Access the Solver feature.

2nd F SOLVER

1-2Select Newton's method for solving.

2nd F SOLVER A

2

This screen will appear a few seconds after “SOLVER” is dis- played.

1-3Enter the formula A = 21 h(b+c).

ALPHA

 

A

 

ALPHA

 

=

1

 

a/b

2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ALPHA

 

H

 

(

 

ALPHA

 

B

 

+

 

 

ALPHA

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C

 

 

)

 

 

 

 

 

 

 

 

 

 

 

 

 

1-4Enter the values: A = 25, B = 5, C = 7

ENTER 2 5 ENTER

5 ENTER 7

ENTER

5-3

Page 17
Image 17
Sharp EL9900 manual 1Access the Solver feature