The world’s Largest Sharp Brain Virtual Experts Marketplace Just a click Away
Levels Tought:
Elementary,Middle School,High School,College,University,PHD
| Teaching Since: | Apr 2017 |
| Last Sign in: | 103 Weeks Ago, 3 Days Ago |
| Questions Answered: | 4870 |
| Tutorials Posted: | 4863 |
MBA IT, Mater in Science and Technology
Devry
Jul-1996 - Jul-2000
Professor
Devry University
Mar-2010 - Oct-2016
Can you explain how to do problems 4 and 5 on my discrete math homework?
Â
ECS20Homework 6Exercise 1Prove or disprove each of these statements about the floor and ceiling functions.a)x⎢⎣⎥⎦⎡⎢⎤⎥=x⎢⎣⎥⎦for all real numbersx.b)xy⎢⎣⎥⎦=x⎢⎣⎥⎦y⎢⎣⎥⎦for all real numbersxandy.c)⎡ ⎤⎣ ⎦⎣ ⎦xx=for all positive real numbersx.Exercise 2Show thatx3isO(x4)but thatx4is notO(x3).Exercise 3a)Show that2x-9isΘ(x).b)Show that3x2+x -5isΘ(x2)c)Show thatx+23⎢⎣⎢⎥⎦⎥isΘ(x)d)Show thatlog10(x)isΘ(log2(x))Exercise 4Letaandbbe two integers. Use a proof by contradiction to show that ifa2-b2+2abis oddthena-bis odd.Exercise 5Use a proof by contradiction to show that:There exists a strictly positive real numberrsuch that for all real numberx, ifx−x⎢⎣⎥⎦<rthen3x⎢⎣⎥⎦=3x.Extra credit:We call a positive integer perfect if it equals the sum of its positive divisors other thanitself.a)Show that 6 and 28 are perfectb)Show that2p-1(2p-1)is a perfect number when2p-1is prime.
Attachments:
-----------