Question

Estimate the limit numerically

lim x→(− Infinity)

(x^4 − 4,000x^3)/
(4x^4 + 9,000)

ANYONE?! nobody can seem to get this one its not 0 or -1/4 either

Answer 1

\[\text{ let } f(x)=\frac{x^4-4000x^3}{4x^4+9000}\]
the limit should be 1/4 ( i know this by short cut way)

Answer 2

but we need to plug in negative "getting big numbers"

Answer 3

\[f(-25)=\frac{(-25)^4-4000(-25)^3}{4(-25)^4+9000}\]
make sure when you enter this into the cal you put paranthesis around the negative part
you know don't do -25^4 but do (-25)^4 or even (25)^4
since (-25)^4=25^4

Answer 4

try it and tell me what you get for x=-25

Answer 5

yea but its -\[\infty\] haha idk how to do that one on a calculator

Answer 6

right

Answer 7

you plug in negative "getting large numbers"

Answer 8

plug in x=-25
then plug in x=-100
then plug in x=-1000
and tell me what f is getting close to