HP 15c Scientific –20, 026–, 027–, 028–, 029–, 030–, 030–, 031–, 032–, 033–, 034–, –10.0000

236 Appendix D: A Detailed Look at _

Return to Program mode and add instructions to your subroutine to eliminate the root just found.

Keystrokes	Display
¥	000-	Program mode.
‚	026–	30 Line before n.
‚

®	027–	34
l0	028–	45 0
-	029–	30
÷	030–	10

Brings x into X-register.

Divides by (x – a), where a is known root.

Now use the same initial estimates to find the next root.

Keystrokes	Display
¥	4.0000	-06	Run mode.
10 “v	–10.0000		Same initial estimates.
20 “	–20
´_2	0.4000		Second root.
O1	0.4000		Stores root for deflation.
))	0.0000		Deflated function value.

Now modify your subroutine to eliminate the second root.

Keystrokes	Display
¥	000-		Program mode.
‚	030–	10	Line before n.
‚
®	031–	34	Brings x into X-register.
l1	032–	45 1
-	033–	30	Deflation for second root.
÷	034–	10