HP HP-11C User Manual

Section 10: Applications Programs 155
The program will halt when the following conditions are satisfied:
1. Loop count = Loop Limit
2. |f(x)|<tolerance (¢
3. |Xpew —Xo1d < Ax limit
The user may choose values for ¢ and Ax or the program will use
default values.
Equations:
_ fx)
f’(x,‘)
Xit1=X;
This program makes a numerical approximation for the derivative
f'(x) to give the following equation:
f(x;)
f(x;+ &) —f(x))
Xit1 =X~ §;
where 6, =10 ®xyand 5, = x, — x, _,
Note:
e After the program has finished, x for f(x) = 0 will be displayed
and will also be in register 2.
® Error 0 will be displayed if, in the attempt to find a root, there
is a division by zero. If this occurs, try a new guess that is close
to your last guess.
e This program also keeps track of the number of iterations
that take place when trying to find a root. R, is initialized
to 50 (lines 020, 021 and 022) and an error (Error 4) will
occur if that many iterations have taken place. The user
may change the maximum number of iterations by deleting
lines 020 and 021 and keying in the desired number.
® The user may like to see each x;,; as it is found by Newton’s
method. To do this key in [f][PSE]after 2 (at line 047 if no
other modifications have been made to the program).
e If the tolerance is too small, round-off error within the
calculator will become significant and the roots become
erroneous.

HP HP-11C Specifications

General

Brand	HP
Model	HP-11C
Category	Calculator
Language	English