Question

lim x→∞ 10x^3-4/x^2+2x-6

Answer 1

use l'hopitals rule. do you know of it?

Answer 2

not really? could u please explane it to me?

Answer 3

you take the derivative of the top and make that the numerator, then you take the derivative of the bottom, and put that as the denominator. then you try to plug infinity in. if it is still inconclusive, you take the derivative again.

Answer 4

L'H: lim as x->infinity 30x/2x +2. plug infinity in, its still infinity over infinity. lhopital's again.
L'H: lim as x->infinity 30/2

Answer 5

do i always use l'hopitals rule to find a lim?

Answer 6

nope, not always. usually you would try to plug in what x is approaching. but in this case, when you plug in infinity, it equals \[\infty/\infty\]

Answer 7

and when that happens, you can use lhopitals (:

Answer 8

thanx a lot! it helps a lot! :) u could be a good teacher! :)

Answer 9

thank you (:

Answer 10

This limit should go to infinity since the power for the numerator is greater than the denominator. @Jesssica, you made a mistake reading the problem =P

Answer 11

ah i did ! haha oops (:

Answer 12

mmhm so actuallyyy it ends up
L'H: 30x^2/2x + 2
L'H: 60x/2
and plugging infinity into that equals infinity .

Answer 13

Yup =)