Recent content by mathematicsma

  1. M

    Medical Thinking purely in words, how this works

    Very interesting points. I sometimes wonder about that, too. Who am I? In other words, which part of me is the self and which part is external? Obviously, everything going on inside my brain comes from me, but it often seems that there is some part of the brain that is more central to my...
  2. M

    Medical Thinking purely in words, how this works

    I know this is an old thread, and this is only a tangential topic, but it's been something I've always wondered about: For those of us who think mostly in words, and have conversations with ourselves, do you refer to yourself as "you" in your thoughts? When I am thinking through an issue...
  3. M

    On differential equations texts

    Thanks. I didn't know about that site, I might actually use it. Does anyone know anything about the differences between the different editions? I have used books (Calculus -Larson, for example) where there are absolutely no changes from one edition to the next other than nicer graphics. Even...
  4. M

    On differential equations texts

    I have a feeling this is the wrong place to post this. I can never figure out where to put things :confused: Anyway, my professor uses the 4th edition of Edwards and Penney Differential Equations and Boundary Value Problems (https://www.amazon.com/gp/product/0131561073/?tag=pfamazon01-20)...
  5. M

    What is the 2/3 the Average Experiment and How Can You Help?

    Redbelly: when I first heard the experiment, I immediately thought I should choose zero. Then, like you, I realized that if even one person doesn't think like me, and chooses another number, my results are off. Like you, until I did some research, I never imagined it would be so high. Note that...
  6. M

    What are the characteristics of the human mind?

    I second drankin. Anyway, what is the mind? It's just a word people throw around, so I'm not sure how to characterize it.
  7. M

    What is the 2/3 the Average Experiment and How Can You Help?

    Okay, the experiment is over. I thank everyone who participated, you all helped. I ended it about a week ago, but then finals caught up with me, and I didn't have a chance to follow up. So here it is: The official results...
  8. M

    Linear Algebra Proof, Hermitian Matrices

    I didn't check all your work, but my initial reaction: all four matrices have to be complex matrices, that's the initial condition. If they're not complex, the conjugate transpose is the same as the transpose, and they're just simple symmetric matrices. Am I wrong?
  9. M

    Linear Algebra Proof, Hermitian Matrices

    I just realized something: If AB=(AB)*=B*A*=BA, then AB commutes. But that is only true if A, B, and AB are all Hermitian. Alternatively, we can say that if A, B are both Hermitian and AB commutes, then AB=BA=B*A*=(AB)*, so we know that AB is Hermitian. That's why the property I cited from...
  10. M

    Linear Algebra Proof, Hermitian Matrices

    Sorry about forgetting the brackets. I fixed that. Okay, (XY)*=Y*X*. So we can rewrite as AD-(CB)*=I. But how does that help? My main problem is that we don't know that any of the individual matrices A, B, C, D are Hermitian. If we could prove that, we're done. B*C* is the same as BC...
  11. M

    Linear Algebra Proof, Hermitian Matrices

    Homework Statement Let A, B, C, D be nxn complex matrices such that AB and CD are Hermitian, i.e., (AB)*=AB and (CD)*=CD. Show that AD-B*C*=I implies that DA-BC=I The symbol * indicates the conjugate transpose of a matrix, i.e., M* is the conjugate transpose of M. I refers to the identity...
  12. M

    What is the 2/3 the Average Experiment and How Can You Help?

    Point well taken. You're correct on both counts. I meant fractions that cannot be expressed as integers between 0 and 100.:approve: And I guess if you're around the area between zero and one, then precision starts to matter.
  13. M

    I'm finally coming out of the closet, atheism I mean.

    That's a beautiful quote from Carl Sagan. I enjoyed it, and I think it's a powerful thought. That said, I'm not sure what it has to do with winning or losing the cosmic lottery. I'm not trying to say that we should all be depressed, or think that life is terrible because it could be so much...
  14. M

    What is the 2/3 the Average Experiment and How Can You Help?

    Interesting thought. Oh well, there's no prize. Other than the ability to pat yourself on the back and convince yourself you're a genius. Then, since you're so darn good at anticipating the behavior of others, become a day trader on the stock markets, or trade currency options, or something...
  15. M

    I'm finally coming out of the closet, atheism I mean.

    OP: whatever you decide, don't bother with quoting bararantok to your parents. It's a complete waste of time. Do NOT try to convince your parents that you are right. The only thing that'll cause is more of a confrontation. You'll be a threat to them. Besides, it's a complete waste of time to...
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