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dhaval0704
Posts: 14
Posted 17:58 Mar 08, 2016 |

I can not solve homework 3 examples because when i am going to find the mod of numbers, calculator gives me math error.

so how can i find mod in final exam?

Can we allow to use pc of campus?

 

 

 

layla08
Posts: 70
Posted 18:02 Mar 08, 2016 |

I talked to Dr. Guo during office hours and she said that we'll have to use a more powerful calculator on test day. If your laptop can solve it, your calculator should be able to as well. I borrowed my friend's calculator and I don't get a MATH ERROR on his. 

For problems that your laptop can not solve however, that probably means you'll have to reduce or simply using one of the theorems we learned during the second half of the quarter. 

Hope that helps!

dhaval0704
Posts: 14
Posted 18:06 Mar 08, 2016 |

Have you used  casio fx-991MS or fx-991ES to solve this problem?

layla08
Posts: 70
Posted 18:13 Mar 08, 2016 |

Doesn't work on a Casio fx-991es. 

dhaval0704
Posts: 14
Posted 18:41 Mar 08, 2016 |

Which calc are u using?

Reem.m
Posts: 12
Posted 23:39 Mar 08, 2016 |

Yes please could you kindly let us know which calculator you are using.

layla08
Posts: 70
Posted 08:55 Mar 09, 2016 |

I'm borrowing a graphing calculator (TI-83) to do high exponents. 

Reem.m
Posts: 12
Posted 15:09 Mar 09, 2016 |

Thank you .

vdikshit
Posts: 5
Posted 19:05 Mar 09, 2016 |

I have the same calculator but its giving me error for calculating  49^191 mod 416 

Its giving me error .Does ur calculator calculates it correctly.

Last edited by vdikshit at 19:07 Mar 09, 2016.
bseemscs
Posts: 26
Posted 22:47 Mar 09, 2016 |

You have to use the third property of modular arithmetic and the properties of exponents to break it down.

Find how big the exponent can be that your calc can handle and break it into those size chunks. My calc can handle 49^7 before error. Note 191 / 7 = 27 R 2 so start with (49^7)^27 = 49^189 and break it into smaller chunks.

49^191 mod 416 = [(49^189 mod 416)(49^2 mod 416)] mod 416 = [(49^7 mod 416)^27 mod 416 (49^2 mod 416)]mod 416 = [(49^27 mod 416) (49^2 mod 416)] mod 416

= [(49^7 mod 416)^3 mod 416 (49^6 mod 416) (49^2 mod 416)] mod 416 = [(49^3 mod 416) (49^6 mod 416) (49^2 mod 416)] mod 416 = [(337) (1) (321)] mod 416 = 17 

alzayer13
Posts: 9
Posted 16:39 Mar 11, 2016 |
layla08 wrote:

I'm borrowing a graphing calculator (TI-83) to do high exponents. 

Can you please  explain how to use (TI-83) calculator  to calculate mod? 

dhaval0704
Posts: 14
Posted 16:43 Mar 11, 2016 |

Now you can use laptop to calculate mod