D-1
D
More about Solving
This appendix provides information about the SOLVE operation beyond that given in
chapter 7.
How SOLVE Finds a Root
SOLVE first attempts to solve the equation directly for the unknown variable. If the
attempt fails, SOLVE changes to an iterative(repetitive) procedure. The
iterative
operation is to execute repetitively the specified equation. The value returned by the
equation is a function
f(x)
of the unknown variable
x
. (
f(x)
is mathematical shorthand
for a function defined in terms of the unknown variable
x
.) SOLVE starts with an
estimate for the unknown variable,
x
, and refines that estimate with each successive
execution of the function,
f(x)
.
If any two successive estimates of the function
f(x)
have opposite signs, then SOLVE
presumes that the function
f(x)
crosses the
x
–axis in at least one place between the
two estimates. This interval is systematically narrowed until a root is found.
For SOLVE to find a root, the root has to exist within the range of numbers of the
calculator, and the function must be mathematically defined where the iterative
search occurs. SOLVE always finds a root, provided one exists (within the overflow
bounds), if one or more of these conditions are met:
Two estimates yield
f(x)
values with opposite signs, and the function's graph
crosses the
x
–axis in at least one place between those estimates (figure a,
below).
f(x)
always increases or always decreases as
x
increases (figure b, below).
The graph of
f(x)
is either concave everywhere or convex everywhere (figure
c, below).
Summary of Contents for 35s
Page 1: ...HP 35s scientific calculator user s guide H Edition 1 HP part number F2215AA 90001 ...
Page 14: ...12 Contents ...
Page 15: ...Part 1 Basic Operation ...
Page 16: ......
Page 46: ...1 30 Getting Started ...
Page 63: ...RPN The Automatic Memory Stack 2 17 A Solution ...
Page 64: ...2 18 RPN The Automatic Memory Stack ...
Page 74: ...3 10 Storing Data into Variables ...
Page 180: ...12 14 Statistical Operations ...
Page 181: ...Part 2 Programming ...
Page 182: ......
Page 246: ...15 12 Solving and Integrating Programs ...
Page 270: ...16 24 Statistics Programs ...
Page 284: ...17 14 Miscellaneous Programs and Equations ...
Page 285: ...Part 3 Appendixes and Reference ...
Page 286: ......
Page 308: ...B 8 User Memory and the Stack ...
Page 322: ...C 14 ALG Summary ...
Page 336: ...D 14 More about Solving ...
Page 346: ...E 10 More about Integration ...
Page 352: ...F 6 Messages ...
Page 370: ...G 18 Operation Index ...
Page 382: ...Index 12 ...