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Maths Help

  • 10-04-2004 2:46pm
    #1
    Closed Accounts Posts: 22


    Some Help with the following would be appreciated (mixture of first year Analysis and Algebra):

    A = ﴾ 2 –1 ﴿
    ﴾ 3 4 ﴿

    A is a matrix


    - Find the eigenvalues and eigenvectors of A.
    - Write down an invertible matrix E, and a diagonal matrix D, such that A=EDE-1

    Calculate An and hence or otherwise solve the recurrence relation

    Xn+1 = 2Xn – Yn
    Yn+1 = -3Xn + 4Yn

    given that X0 = 2, Y0 = 1.

    2. Use the cross product to find all the solutions of the system of linear equations

    X1 + 3X2 + 4 X3 = 0
    2X1 + 4X2 - 3X3 = 0

    3. State the Well-ordering Axiom for Z (integers), and show that it fails for Q (rationals).

    4.
    - Use the Sieve Method to find all the primes in the interval [8,96]

    - Prove that there are infinitely many primes of the form 4q + 3,
    where q is a positive integer.

    - Prove that 7^1/2 is irrational.

    5.
    - Prove that if a sequence is increasing and bounded above then it converges.

    - The sequence (an ) is defined by a1 = 2, an+1 = (an + 6)1/2 (n is greater thatn or equal to 1).
    (1) Calculate a few terms and guess the behaviour of the sequence.
    (2) Given that the sequence converges, find its (positive) limit.
    (3) Now show that part (a) applies, so that the sequence does indeed converge.

    6.
    -What does it mean to say that the function f is continuous at c in (a,b)? Use the limit theorems to show that f defined by

    f(x) = x5 – 3x4 + 1

    is continuous at 2.

    - State the Intermediate Value Theorem and use it to show that the polynomial above (f(x) = x5 – 3x4 + 1) has a root in [-1,0] and another in [0,1].

    - Outline a proof of the Intermediate Value Theorem.

    7.
    - The function g is defined on (1,3) by

    g(x) = {px^2 + x + 3 if 1 < x £ 2
    {3x + q if 2 < x < 3

    - Show that g is continuous on (1,3) if and only if q = 4p – 1. What are the values of p and q if g is differentiable on (1,3)?

    - Prove the Mean Value Theorem, assuming Rolle’s Theorem.
    - The function f satisfies f’(x) > 0 for all x in (1,2). Show that f is increasing on (1,2).

    8.
    - Show using the definition

    lnx = {Integral between x and 1} of: (1/t)dt (x > 0),

    that ln(ab) = ln(a) + ln(b) (a,b > 0 )

    Explain briefly why given c there exists d > 0 such that ln(d) = c, and hence define
    the exponential ex.

    - Calculate the lower Riemann sum L(h,p) where h(x) = 1/x and P is the partition of [1,3] into eight equal parts. What does the answer say about the value of e?

    9.

    - Show that the improper integral:

    {Integral between ∞ and 1} of: dx/(x+1)1/2

    diverges.

    - Show also that:

    1/(21/2) + 1/(31/2) +……….+ 1/(n1/2) ≥{Integral between n and 1}of: dx/(x + 1)1/2 (n≥2)

    and deduce that the series
    ∑1/(n + 1)1/2 [sum starting value is: n = 1, sum ending value is: ∞]

    diverges
    10.

    -Define the Euler ø function.
    Calculate ø(m) when (1) m = 128, (2) m = 24.511.137

    State and prove Euler’s theorem.

    Use Euler’s Theorem (or otherwise) to find the remainder when 2986 is divided by 45.

    Find the missing digit in the ISBN number 3-540-7?1-87-x.


Comments

  • Moderators, Social & Fun Moderators Posts: 10,501 Mod ✭✭✭✭ecksor


    What exactly is that from? You're having problems with all of it?


  • Registered Users, Registered Users 2 Posts: 1,372 ✭✭✭silverside


    can you not sit down with some of the guys in your class and go through it - this should all have been covered in one form or another in your notes/tutorials.


  • Registered Users, Registered Users 2 Posts: 2,648 ✭✭✭smiles


    Looks like an old leaving cert exam paper.

    RTFM.

    (read the book)

    << Fio >>


  • Moderators, Social & Fun Moderators Posts: 10,501 Mod ✭✭✭✭ecksor


    Euler's totient function and Dirichlet's theorem are on the leaving cert syllabus??


  • Closed Accounts Posts: 15,552 ✭✭✭✭GuanYin


    I'm not overly sure this forum exists for people to have their homework done for them.

    I'll give Leavingcert2003 a bit of time to explain what exactly he wants help with before I decide to close this or not.


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  • Closed Accounts Posts: 24 Nowhere man


    there is no way that that is on the leaving certificate course


  • Registered Users, Registered Users 2 Posts: 1,372 ✭✭✭silverside


    nah looks like first year maths somewhere (UCD?)


  • Closed Accounts Posts: 22 leavingcert2003


    First Year NUIG actually. The final exam is on Friday week and I dont have a clue of any of this as I had to miss a lot of lectures. I really need help with this. Please


  • Registered Users, Registered Users 2 Posts: 1,372 ✭✭✭silverside


    You wont learn this off boards. Get the tutorial notes of one of your classmates and study them like crazy. Do all the past papers you can. If they are nice to you they may help you out by explaining them. What were you doing all year if you cant answer any of these?


  • Registered Users, Registered Users 2 Posts: 2,648 ✭✭✭smiles


    Originally posted by leavingcert2003
    First Year NUIG actually. The final exam is on Friday week and I dont have a clue of any of this as I had to miss a lot of lectures. I really need help with this. Please

    Right, well being a lovely nice NUIG student (and freakily organised) I've got all the notes from last years Algebra & Analysis (Johnny Burns / John McDermott / Ted Hurley / McCloskey) and all the exam papers done out.

    I can bring 'em up to galway (heading down tonight/tomorrow) if you want to "borrow" em.

    Plus I give remarkably cheap grinds..... (average of 95% in those exams)

    PM me if you want the note or help

    << Fio >>


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