Results 1 to 5 of 5

Math Help - Limits

  1. #1
    Junior Member
    Joined
    Sep 2007
    Posts
    69

    Limits

    1. )Let f(x)=3 x^9 -10 x^3 +2 and g(x)=cx^n -7 x^3 +18 with c cannot = 0. Then

    lim (-->infinite) f(x)/g(x)= infinite

    c (>, < or =) to ________ and n (>, < or =) to ________ .


    2.)The function

    f(x)= -4x^2+4 if x >(and equal to) -2
    d-x if x -2

    is continuous at x=-2 if and only if d = _______________


    3.) The set of all points of discontinuity of the function

    g(x)= x+4 / x^2-16

    equals
    a) {4}
    b) {4,-4 }
    c) {-4 }

    sorry..hope you understand the notations...
    Last edited by lemontea; May 19th 2008 at 12:10 AM.
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor kalagota's Avatar
    Joined
    Oct 2007
    From
    Taguig City, Philippines
    Posts
    1,026
    sorry, can't understand your post..
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Junior Member
    Joined
    Sep 2007
    Posts
    69
    sorry..i edited it..hope you understand it now
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Moo
    Moo is offline
    A Cute Angle Moo's Avatar
    Joined
    Mar 2008
    From
    P(I'm here)=1/3, P(I'm there)=t+1/3
    Posts
    5,618
    Thanks
    6
    Hello,

    1. )Let f(x)=3 x^9 -10 x^3 +2 and g(x)=cx^n -7 x^3 +18 with c cannot = 0. Then

    lim (-->infinite) f(x)/g(x)= infinite

    c (>, < or =) to ________ and n (>, < or =) to ________ .
    Polynomial=a_n x^n+a_{n-1} x^{n-1}+\dots+a_1 x+a_0

    a_n \neq 0

    a_n is the leading coefficient.
    n is the degree of the polynomial.


    The limit of the quotient of two polynomials is :

    - infinity if the degree of the polynomial above is superior to the degree of the polynomial below. The sign of it depends on the leading coefficient.
    - the quotient of the leading coefficients if the leading coefficients above and below are the same.
    - 0 if the degree of the polynomial below is superior to the degree of the polynomial above.

    2.)The function

    f(x)= -4x^2+4 if x >(and equal to) -2
    d-x if x -2

    is continuous at x=-2 if and only if d = _______________
    For this to be continuous, you must have :

    \lim_{x \to 2^-} f(x)= \lim_{x \to 2^+} f(x)

    \Longleftrightarrow \lim_{x \to 2} \ d-x=\lim_{x \to 2} \ -4x^2+4

    Just replace and find the value of d

    3.) The set of all points of discontinuity of the function

    g(x)= x+4 / x^2-16

    equals
    a) {4}
    b) {4,-4 }
    c) {-4 }
    Change the denominator into x^2-16=(x-4)(x+4).
    Simplify, and then conclude
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Junior Member
    Joined
    Sep 2007
    Posts
    69
    i don't get the 2nd question...how do i replace and find the value of d?...
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. Using limits to find other limits
    Posted in the Calculus Forum
    Replies: 7
    Last Post: September 18th 2009, 05:34 PM
  2. Function limits and sequence limits
    Posted in the Differential Geometry Forum
    Replies: 0
    Last Post: April 26th 2009, 01:45 PM
  3. HELP on LIMITS
    Posted in the Calculus Forum
    Replies: 4
    Last Post: September 23rd 2008, 11:17 PM
  4. Limits
    Posted in the Calculus Forum
    Replies: 5
    Last Post: September 21st 2008, 10:52 PM
  5. [SOLVED] [SOLVED] Limits. LIMITS!
    Posted in the Calculus Forum
    Replies: 1
    Last Post: February 25th 2008, 10:41 PM

Search Tags


/mathhelpforum @mathhelpforum