Coincidental numbers

Thread Starter

neonstrobe

Joined May 15, 2009
131
Just checking an algorithm I stumbled on a slightly interesting result. The expression is
5/(1.5**4).
Needs answer to 9 decimal points.
 

dl324

Joined Mar 30, 2015
12,241
What makes it interesting? There's no way to get the wrong answer because they included parenthesis to force an order of operations that's already understood.
 

Thread Starter

neonstrobe

Joined May 15, 2009
131
Sorry. I'll rephrase that in Basic: 5/1.5^4 (without redundant parentheses).
Just means raise to the power. It's the Fortran version.
 

Wendy

Joined Mar 24, 2008
22,205
\(x=\frac{5}{1.5^4}\)

Practicing my LaTex skills.

temp.png

The M$ calculator can handle more than 8 digits.

I get 0.98765432098765432098765432098765
 
Last edited:

Wendy

Joined Mar 24, 2008
22,205
\(\frac{987654321}{123456789}=8.000000072900000663390006036849\)

Trolling Moderator style.
 
Last edited:

wayneh

Joined Sep 9, 2010
16,513
\(\frac{987654321}{123456789}=8.000000072900000663390006036849\)

Trolling Moderator style.
Just curious. What did you use to get that many digits? Excel drops anything past 729. Another calculator I have gives ...72900001 using double precision and ...72900000664 using float80.
 
Last edited:

Thread Starter

neonstrobe

Joined May 15, 2009
131
\(x=\frac{5}{1.5^4}\)

Practicing my LaTex skills.

View attachment 227764

The M$ calculator can handle more than 8 digits.

I get 0.98765432098765432098765432098765
Yes, that's why I said to 9 decimal digits of precision. The repeat count gets approximated.
Could not have been exact with a factor of 3 in the denominator, really!
My old calculator displays 9 digits but has an accuracy to about 12. You have to subtract some MSD's to see the remainder. Which is how I came across this.
 
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