Appendix D: A Detailed Look at _ 229

Keystrokes

Display

 

¥

 

Run mode.

7 v

7.0000

Initial estimates.

14

14

 

´_2

10.0000

Possible root.

))

1,000.0000

Stress not zero.

The large stress value at the root points out that the _ routine has found a discontinuity. This is a place on the beam where the stress quickly changes from negative to positive. Start at the other end of the beam (estimates of 0 and 7) and use _again.

Keystrokes

Display

 

0 v

0.0000

Initial estimates.

7

7

 

´ _ 2

3.1358

Possible root.

))

2.0000

-07Negligible stress.

Beame's beam has zero shear stress at approximately 3.1358 meters and an abrupt change of stress at 10.0000 meters.

When no root is found and Error 8 is displayed, you can press or any one key to clear the display and observe the estimate at which the function was closest to zero. By also reviewing the numbers in the Y- and Z- registers, you can often determine the nature of the function near the root estimate and use this information constructively.

Page 229
Image 229
HP 15c Scientific manual 000.0000, Initial estimates, 1358, Possible root, Negligible stress