HP HP-65 - Page 27

X - Reverses division operation:
you are back where you
started.
B B Retrieves last number dis-
played before multiplica-
tion operation.
- - Correct operation produces
desired results.
If you want to correct a number in a long calculation, Last X
can save you from starting over. For example, divide 12 by 2.157
after you have divided by 3.157 by mistake.
Press See Displayed Comments
12 [ENTER4 3.157 You wanted to divide by
= 3.80 2.157, not 3.157.
B - Retrieves last number dis-
played preceding operation.
X - You’re back at the beginning.
2.157 = ETE Correct operation produces
desired results.
Another, and possibly more important, use for Last X is in
functions where X appears more than once. Without going into
details since we have not yet discussed functions, examples might
bel ginx
X’
y* — VX, sin X 4 cos® X
In each case x is saved in Last X after the first operation is per-
formed.
The following operations (including inverses) save x in
Last X:
#,5 %, B, oms], (oms+], [int], [1n],
,[5%],[aBS] . Note that [CLX does not affect the
Last X register.