ln and e^x on the 16C?

[Gerson W. Barbosa]

(03-23-2016 12:25 AM)Bob Patton Wrote:  Here's a crude algo I developed for 4 -bangers with memory. It might be a start.
Natural log ln(v)
0.6 to 1.65, 6 digits, 39 keystrokes

y = -(v - 1)/(v + 1) = -((v + 1) - 2)/(v + 1)
ln(v) = ((((5y^2/7) - 1)^(-1) X 42 - 8)y^2 / 75 - 2)y

Since √x is available on the HP-16C, the following might be an option, for this level of precision:

Code:


000- g LBL A
002- g SQRT
003- g SQRT
004- g SQRT
005- g SQRT
006- g SQRT
007- g SQRT
008- g SQRT
009- g SQRT
010- g SQRT
011-   2
012-   *
013-   1
014-   -
015- g SQRT
016-   1
017-   -
018-   5  
019-   1
020-   2
021-   *
022- g RTN

0.600 GSB A -> -0.510825830

1.125 GSB A --> 0.117783552

1.650 GSB A --> 0.500775424