1. B

    Basic Permutation Questions - wondering if I am on the right track

    Hi I have got some basic example questions and I am hoping someone could let me know if I am on the right track! Qu1(a) How many different ways can the letters in the word wombat be arranged: I thought this was simply 6! from (6 choose 1; 5 choose 1; 4 choose 1; 3 choose 1 and 1 choose 1)...
  2. O

    Wondering if someone can help me out by marking a few questions I've done - Functions

    I've done all the questions (I think), and I don't really get detailed info back from my teachers in this course, so I was hoping somebody could mark these for me, and tell me what I've done wrong, and why, and how I can fix it. It's a little unorthodox, I suppose, but I'd really appreciate the...
  3. L

    Found Answer but Wondering how, more integration

    \int {(15sinx+6tanx)}dx So I broke it up 15 \int {sinx} + 6 \int {tanx} Then got... {-15cosx-6ln|cosx|} I know its right however I don't know if I was taught the integral of tanx, so I was wondering if there was any other way of doing it?
  4. I

    Wondering if I did these correctly

    Hello everyone! I solved (or rather, tried to) a couple of problems, and I was wondering if I attempted them correctly. Any feedback would be wonderful! Thank you in advance! 1) Suppose the p.d.f. of X is f(x) = 1/2x for 0 < x < 2 and 0 otherwise. Determine the p.d.f. of Y = 3X + 2. My...
  5. N

    I have always been wondering about this (integrals)

    Ok, so let's assume we have the function f(x). If we want to find the derivative, we write f'(x). If we want to find the derivative of this as well, we write f''(x), right? Now, let's go back to f(x). If we want to integrate this, we write F(x). Now, if we want to integrate F(x) again, how...
  6. O

    Thanl you for replying, I was wondering....

    I have some other questions, but just to make sure I want to see if got the right answers... -to solve the inequality |x + 1| + |2x - 1| < 10 -write an equation through the point (1,2); one which is perpendicular to the line y=2x + 3 -write an equation through the point (1,2); one which...
  7. T

    Wondering if this is a typo?

    Not a typo most likely, so now don't know how to solve. Let p be prime. Assume that \sum_{k=0}^pa^{2k-1} \equiv 0 mod p. Show that p = 2 or p = 3. I can prove this for \sum_{k=1}^pa^{2k-1} \equiv 0 mod p(notice the summation goes from 1 to p instead of 0 to p). I was just wondering if...
  8. T

    Wondering if a difference of 1 in a relation affects my proof

    Let k,n be integers such that 1 <= k <= n <= p-1 where p is prime. Assume (a,p) = 1. Show that ak \equiv an mod p iff k = n. Proof: ak \equiv an mod p k \equiv n mod p (since (a,p) = 1) Then I used a Lemma that states: Let i and j be integers with 1 <= i <= j <= m. If i \equiv j mod m, then i...
  9. D

    Just wondering

    Find the domain and range of the function: f(x) = x^2 + 11 I have the domain as (-∞,∞) and the range as (11,∞). did I get them right?
  10. M

    wondering about this inequality

    If \frac{x}{x+8}\leq\frac{1}{x-1}, find the set of values of x such that the inequality is valid . My working : (x(x-1))\leq (x+8) x^2-2x-8 \leq 0 -2 \leq x\leq4---- my answer But the book says the set of values of x is { x: -8<x \leq -2 or 1<x\leq 4 } where did i go wrong again
  11. E

    Wondering if I did this right..

    f(x) = 2x sqrt(x^2-1) I got my answer as (4x^2 - 2)/sqrt(x^2 - 1).. IS it right?? Or is the answer (4x^2 - 1)/sqrt(x^2 - 1)??
  12. S


    Hello, Just wondering I placed three threads on this forum and did not get a reply. Was my question unclear or did I not state my HW problem answer properly? Just trying to get some help and it appears that many have reviewed the post but no replies. Just wondering Thanks Scarter
  13. P

    Hi, new here! Was wondering if I am right, I would

    I would rather try things out as far as they can go, and then ask for help! I am having problems on a statistics problem, that goes like this: Suppose that a random variable X observes normal distribution N~(58.2, 12.55). 1)Calculate P(X>25) For this I find the z-score. Z=X-M/S...
  14. slevvio

    just wondering

    A student moving into a new flat buys a box of 20 light bulbs. Unknown to the student, exactly one of the bulbs is defective. Find: b) The conditional probability that the second bulb used is not defective, given that the first bulb used is not defective; If the first bulb is not defective...
  15. S

    i was just wondering if these problems i did were right?

    If A(2, 2), B(5, 5), and C(8, 8), then which is AC - BC? 4 Which value of d makes the graph of the equation 3x - dy = 5d perpendicular to the graph of y = 3x - 4? d = -9 d = 9 d = 6 d = 3 Which values of m and n make the midpoint of AB locate at the origin, given A(m, 11) and B(-5...
  16. dan

    hmmm... just wondering

    is it posible to solve a non-liner system...and how!!! for example x^2 +y^3 =10 x^3 -y^4 =-6 if any one has any thoughts on how you do this please let me know ~dan