Recent content by Juanriq

  1. J

    Why am I getting ln(2) instead of -ln(2) in this integral?

    Looks good!
  2. J

    Why am I getting ln(2) instead of -ln(2) in this integral?

    Right, I didn't notice that the +C was dropped when the evaluating the LOI. My bad
  3. J

    Why am I getting ln(2) instead of -ln(2) in this integral?

    Hello again! There's a couple things wrong notationally with the first problem. You shouldn't really have both u's and x's in the same integral, although your simplification is correct. Also, the whole third line...bad! This is a definite integral (that means is has limits of integration...
  4. J

    What Are Some Normal Subgroups of D4?

    In order for it to be a subgroup, don't forget that it has to contain the identity.
  5. J

    Stabilizer subgroup of an element in a permutation group

    Ohhhhh... that's something completely different than what I was thinking. Thanks lanedance!
  6. J

    Anti-Derivatives with Substitution: Solving x^2(1-x)^8dx

    You got it!
  7. J

    Anti-Derivatives with Substitution: Solving x^2(1-x)^8dx

    You get du = -dx. This implies that -du = dx as well. The intermediate step in your solution would be - \int u^8 - 2u^9 + u^{10} du = \int - u^8 + 2u^9 - u^{10} du and you would break up the integrals from there. LaTex isn't so bad to learn! I guarantee that it takes less time than paint =)
  8. J

    Anti-Derivatives with Substitution: Solving x^2(1-x)^8dx

    Actually all the signs are bacwards, you lost the negative sign right after your first equal sign.
  9. J

    Anti-Derivatives with Substitution: Solving x^2(1-x)^8dx

    Also, I commend you on using paint. That takes dedication!
  10. J

    Anti-Derivatives with Substitution: Solving x^2(1-x)^8dx

    No that is fine! You can simplify the -2/10 to -1/5, and rewrite the terms in order of decreasing exponents, but only the evilest of teachers would expect you to expand those terms!
  11. J

    Anti-Derivatives with Substitution: Solving x^2(1-x)^8dx

    Thats absolutely right. a lot of people don't even see making the substitution for x afterwards, they get stuck after the u-substitution.
  12. J

    Stabilizer subgroup of an element in a permutation group

    the inverse of G_a is the identity?
  13. J

    Stabilizer subgroup of an element in a permutation group

    so if a=(321), then g(321) = (321), right?
  14. J

    Anti-Derivatives with Substitution: Solving x^2(1-x)^8dx

    Hey a Munk3y, it looks good exceot for the multiplication of (1-u)^2u^8. try expanding the squared term first...
  15. J

    Stabilizer subgroup of an element in a permutation group

    Hey guys, I think I don't understand what this subgroup does. Lanedance, I think I see what you mean, but wouldn't that just be like an identity group? I don't understand what would be so special about some group that just spits the same thing back out all the time... Also, micromass, I have...
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