Post a New Question

math

posted by on .

how would I do this limit?(by the way
-> is an arrow(

lim x-> 0 (5x^3+8x^2)/ (3x^4 - 16x^2)

  • math - ,

    When both the numerator and denominator evaluate to zero or infinity, the limit can be found by applying the d'hôpital rule.

    The rule states that if the limit of a division is indeterminate, the limit of the derivatives of the numerator and the denominator will equal the limit in question. The rule can be applied successively until either the denominator becomes defined and non-zero.

    For the case in point,
    let
    numerator=f1(x)=(5x^3+8x^2)
    denominator=f2(x)=(3x^4 - 16x^2)
    Since f2(0)=0, we need to find the derivative
    f21(x)=d(f1(x))/dx=12x^3-32x.
    Again f21(0)=0, so we find the derivative
    f22(x)=d²(f2(x))/dx²=36x²-32
    f22(0)=-32
    Now we have to evaluate
    f12(x)=d²(f1(x))/dx²=30x+16
    f12(0)=16
    Therefore the limit x→0
    (5x^3+8x^2)/ (3x^4 - 16x^2)
    =f12(0)/f22(0)
    =16/(-32)
    =-(1/2)

Answer This Question

First Name:
School Subject:
Answer:

Related Questions

More Related Questions

Post a New Question