## View Poll Results: What is the hardest math you learned?

Voters
105. You may not vote on this poll
• Calculus (specify in comments)

38 36.19%
• Trigonometry

11 10.48%
• (Enriched) Geometry

11 10.48%
• Equations (specify)

4 3.81%
• Graphing Equations (specify)

2 1.90%
• Basic Algebra (specify)

7 6.67%
• I can do better!

24 22.86%
• What kind of math is that?!

8 7.62%

# Thread: Calculator/Math Thread

1. Not math but I hope someone can help, just working on the synthesis of Hexaphenylbenzene for a chemistry lab, and I was just wondering if this mechanism seems reasonable?

**I really wasn't sure about the E1CB OH elimination **

PS: Ignore the names of the products they are a joke for my teacher

Spoiler:

edit:
Originally Posted by blakedacuber
integrate ( x^(1/2) + 1/x^(1/2) ) dx with the limits 4 and 1
Spoiler:

2. Originally Posted by vcuber13
Not math but I hope someone can help, just working on the synthesis of Hexaphenylbenzene for a chemistry lab, and I was just wondering if this mechanism seems reasonable?

**I really wasn't sure about the E1CB OH elimination **

PS: Ignore the names of the products they are a joke for my teacher

Spoiler:

edit:

Spoiler:

Thanks

3. Math videos are now on my channel!

4. Found nice tutorials on MIT Youtube channel. Really worth checking them out!

Also, looking for a proof for this:

5. Just got this question in my discrete math class homework lol.

Spoiler:

When one disassembles a standard 3X3X3 Rubik's Cube one discovers that it is just a fixed
3D cross connecting the center squares, and a bunch of edge and corner pieces that move
around the stationary cross. Consider the state diagram for the conguration space of all
assembled cubes, that is one state for each and every possible way of putting the cube back
together. In order not to count a state multiple times (eg placing it upside down) we will x
the orientation of the center squares (ie the red center square will always be up and the blue
center square will always be to the right).
(a) Write down an expression for the number of nodes/states of this diagram, explaining the
reasoning for each term. How many decimal digits does this number have? Is it feasible
to keep track of all the nodes?
(b) Consider all of the obvious legal (without disassembly) basic minimal moves/actions/edges
for going from one assembled state to another (while preserving our fixed orientation of
the center squares). What are these moves? How many arrows/edges are there leading
out of each node? and how many are leading in? [Note: the diagram is not connected
since one can assemble unsolvable cubes.]
(c) For these actions how many times does one have to repeat such an action to get back to
the original state?

Edit: Text didn't paste perfectly and might be some words missing but I thought it was cool I got a rubiks cube question.

6. Originally Posted by Hyrtsi
Found nice tutorials on MIT Youtube channel. Really worth checking them out!
I just watched one and it's fantastic, the best video I've seen in a long time:
http://www.youtube.com/watch?v=wsOoClvZmic

7. From http://www.speedsolving.com/forum/sh...93#post721993:

Originally Posted by Keroma12
Anybody know how to prove det(AB) = det(A)*det(B) using only the permutation definition of the determinant function? Completely forgotten how to type in math here, otherwise I would type out the definition. http://en.wikipedia.org/wiki/Leibniz...r_determinants

(I am aware that this is a terrible way to prove this and that there are much much nicer ways.)

8. Hardest? Doesn't matter. I had my most fun learning about groups with my cube in hand

9. Somebody do what is in my signature, and you'll be a millionaire

10. Originally Posted by theZcuber
Somebody do what is in my signature, and you'll be a millionaire
I would spend a lifetime with those problems. But not for the money, there are far better reasons to do that.

#### Posting Permissions

• You may not post new threads
• You may not post replies
• You may not post attachments
• You may not edit your posts
•