JPHamlett
2015-03-27 00:08:22
So I have been staring at this for a while now and can't figure out where to start.
1. Let g be a function from set A to B, and f be a function from B to C. Prove or Disprove the following statement
f of g is bijective iff f is bijective and g is bijective.
2. Place as small an upper bound as you can on the number of turns required to solve the white cross on Rubik's cube. Justify your answer.
Don't need a walkthrough, just a place to start.
yourule97
2015-03-27 08:53:46
I have no idea how to approach number 2, but I have found some quantitative sources on the "God's Number." Its a little over my head right now, but you can take a look:
http://www.cube20.org/http://www.cubezone.be/crossstudy.htmlI hope it helps
JPHamlett
2015-03-27 09:17:42
From: yourule97
I have no idea how to approach number 2, but I have found some quantitative sources on the "God's Number." Its a little over my head right now, but you can take a look:
http://www.cube20.org/
http://www.cubezone.be/crossstudy.html
I hope it helps
I don't know either lol, Googleing found that it is 8 but I can't prove it.
Any idea on 1?
cosmasjdz
2015-03-27 12:02:17
From: JPHamlett
So I have been staring at this for a while now and can't figure out where to start.
1. Let g be a function from set A to B, and f be a function from B to C. Prove or Disprove the following statement
f of g is bijective iff f is bijective and g is bijective.
2. Place as small an upper bound as you can on the number of turns required to solve the white cross on Rubik's cube. Justify your answer.
Don't need a walkthrough, just a place to start.
Not sure if i correctly understand first one.The part about from set a to b. If set is defined as a part of a function for example from x=5 to x=15. Then any alternating function like sinus for example would make f of g NOT bijective as it would have 2 intersection points within the line on a x axis plane.
ignorant
2015-03-27 14:18:47
From: yourule97
I have no idea how to approach number 2, but I have found some quantitative sources on the "God's Number." Its a little over my head right now, but you can take a look:
http://www.cube20.org/
http://www.cubezone.be/crossstudy.html
I hope it helps
A little off topic but the 1st link is about God's Algorithm which is the maximum number of turns (HTM) required to solve the Rubik's Cube from any state. I believe however the 2nd link contains what OP needs (fixed color cross solving which is white in the case of OP)