X^Y on the Elektronika B3-19M

[Albert Chan]

(08-07-2018 05:23 PM)watchmaker Wrote:  The result of "x^y" differs slightly from the result of "ln"+"*"+"e^x" (unlike B3-21, B3-34!). E. g., 8 | 8 x^y gives 16777188, 8 | 8 ln * e^x gives 16777173. But the same operation with DECIMAL logarithms (8 | 8 lg * | 10 ln * e^x) gives 16777188. Most probably it uses a similar algorithm, directly placing ln(10) in Z.

Perhaps ln(10) is needed to reduce argument for exp(x), for speed and accuracy.

ln(8 ^ 8) = 8 ln(8) = 16.63553233 = 7 ln(10) + 0.517436682

8^8 = 10^7 * exp(0.517436682) = 10^7 * 1.6777216