Unexpected Answer for an Equation

usamrf
3 ●1

Hello,

I am trying to calculate the following equation in SAGE.

N = 100.

p = 0.9.

r = (N /(N-1))*(ln(N)-ln(-ln(p))); r

Unfortunately, sage gives this answer 100/99*log(100) + 2.27309831041661 , which is not the expected answer !!

But, when I used google calculator, I got the expected answer, which is 6.92478536697

Please let me know what is going on.? Thank you.

Comments

To add to the answer below, note that if you enter N as a floating-point number, you directly get what you want:

sage: N = 100.  # Note the '.' after '100'
sage: p = 0.9
sage: r = (N /(N-1))*(ln(N)-ln(-ln(p))); r 
6.92478536697024

B r u n o ( 2016-04-29 14:47:37 +0200 )edit

Thank you Bruno.

usamrf ( 2016-05-01 23:05:03 +0200 )edit

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