Recent content by Justabeginner

  1. J

    Advice for Incoming Undergrad On Post-Baccalaureate Optionality

    I apologize - I meant post-baccalaureate when I said post-doc. I am hoping to graduate early because of loans/lack of FA. I have already studied the major requirements for these colleges, and with placement exams, it already significantly reduces the time I need to graduate. I'm trying to...
  2. J

    Is a B in Calculus 1 and 2 the end for me?

    Don't feel discouraged by this one grade. Use it as a motivator to improve in the courses you're taking now and those you will take in the future. I know of people who have gotten B's in Calc I, and even slightly lower grades in undergrad math, but they went on to obtain PhDs in MIT, Harvard...
  3. J

    Math, Neuroscience, Languages? My brain is overwhelmed

    Thanks for the replies all! I've decided to do a Neuroscience major, but I intend to use my knowledge in upper-level math to find research opportunities in computational neuro.
  4. J

    Advice for Incoming Undergrad On Post-Baccalaureate Optionality

    Hi all! I'm trying to decide between Smith, Wellesley, and Wesleyan. I'm interested in their neuroscience programs, and have heard great things about all of them. However, quite a few factors are at play here: FA, Post-doc optionality if I want to do med school (not sure about career path yet)...
  5. J

    The group operation on G*G is multiplication.

    A = G * G, as in G cross G. I do not understand how T is directly isomorphic to G.
  6. J

    Irreducible Polynomial of Degree 3

    Homework Statement If p(x) ∈F[x] is of degree 3, and p(x)=a0+a1∗x+a2∗x2+a3∗x3, show that p(x) is irreducible over F if there is no element r∈F such that a0+a1∗r+a2∗r2+a3∗r3 =0. Homework Equations The Attempt at a Solution Is this approach correct? If p(x) is reducible, then there...
  7. J

    The group operation on G*G is multiplication.

    Homework Statement Let G be a group, A = G * G. In A, Let T = {(g, g)|g ε G}. Prove that T is isomorphic to G. Homework Equations The Attempt at a Solution A is abelian. Therefore, G * G is abelian. T is a subgroup of G. I am not sure if my above inferences are even correct...
  8. J

    Math, Neuroscience, Languages? My brain is overwhelmed

    I'm interested in studying mathematics at the undergraduate level, and have been studying some upper-level courses on my own (technically, for the college I hope to go to, I would only have six courses left to complete a math major). I also am interested in connecting my knowledge of upper level...
  9. J

    Proof of Group Homework: Ring of 2x2 Matrices over Zp

    Is G, technically the non-abelian group GL(2, R)? I approached this problem in that manner.
  10. J

    Proof of Group Homework: Ring of 2x2 Matrices over Zp

    For A, B in Zp, where p is prime, Det(A)Det(B) = Det(AB).
  11. J

    Proof of Group Homework: Ring of 2x2 Matrices over Zp

    If Det(A) ≠0 and Det(B)≠0, then Det(AB)≠0 too.
  12. J

    Proof of Group Homework: Ring of 2x2 Matrices over Zp

    M has an inverse because M= (a b c d) has another matrix such that M * (other matrix) = Identity Matrix. We know that the det(M-1) ≠ 0 because det(M) ≠0, and 1/det(M)≠0, ever. This ring is specifically an integral domain, I believe. The property of a ring is closure under multiplication and...
  13. J

    Proof of Group Homework: Ring of 2x2 Matrices over Zp

    M * M-1 = I. The original matrix times its inverse is equal to the Identity Matrix. If an element exists, then its inverse must exist because the identity element is always in a group (definition of group). Groups are always closed under products, as well.
  14. J

    Proof of Group Homework: Ring of 2x2 Matrices over Zp

    It means 1*n = n. The identity should be (1 0 0 1). Sorry, I completely forgot to insert them. I failed to mention that the elements are from Zp, p being a prime. Zp is a field if and only if p is prime, and the properties hold true because of this. Since the determinant is nonzero, and...
  15. J

    Proof of Group Homework: Ring of 2x2 Matrices over Zp

    1. Multiplicative identity in a ring is 1, right? But 1 is not in G, because G consists of the set of matrices for which ad - bc ≠ 0, but (1) is not a 2*2 matrix. 2. Yes; [(ab)c]ij = (ab)ik ckj = (ailblk)ckj = ail(blkckj) = ail(bc)lj = [a(bc)]ij 3. Yes, for A= (a b c d), and B= (e f g h), it was...
Back
Top