# \[Bug #913\] mathn $B$7$?\>l9g!"(Bsqrt(NaN) $B$,J#AG?t$K$J$k(B

**URL:** <https://www.ruby-forum.com/t/bug-913-mathn-b-7-l9g-bsqrt-nan-b-j-ag-t-k-j-k-b/156130>\
**Category:** Development\
**Created:** [December 21, 2008, 7:30am UTC](https://www.ruby-forum.com/t/bug-913-mathn-b-7-l9g-bsqrt-nan-b-j-ag-t-k-j-k-b/156130 "2008-12-21T07:30:25Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![tadayoshi\_funaba](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/t/f0a364/32.png) [@tadayoshi\_funaba](https://www.ruby-forum.com/u/tadayoshi_funaba)\
**Post date:** [December 21, 2008, 7:30am UTC](https://www.ruby-forum.com/t/bug-913-mathn-b-7-l9g-bsqrt-nan-b-j-ag-t-k-j-k-b/156130/1 "2008-12-21T07:30:25Z")

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Bug #913: mathn e$B$7$?\>l9g!"e(Bsqrt(NaN) e$B$,J#AG?t$K$J$ke(B  
[http://redmine.ruby-lang.org/issues/show/913](http://redmine.ruby-lang.org/issues/show/913)

e$B5/I\<\<Te(B: tadayoshi funaba  
e$B%9%F!\<%?%9e(B: Open, e$BM%@hEYe(B: Normal

main@191-20081221\> nan = 0.0/0  
#=\> NaN  
main@191-20081221\> Math.sqrt(nan)  
#=\> NaN  
main@191-20081221\> require ‘mathn’  
#=\> true  
main@191-20081221\> Math.sqrt(nan)  
#=\> (0+NaN\*i)