Originally Posted by

**williamb** Consider f(x) = (-4 sqrt(9x**2 + 6) / (-6x-8)

Take steps to find the limit as x -> infinity and –infinity

a) Find the limit of f(x) as x goes to infinity

rewrite the expression sqrt(9x**2 + 6) by extracting x**2 as follows:

sqrt(9x**2 + 6) = sqrt(x**2 ) sqrt(9x**2 + 6) = Ax sqrt(p(x))

p(x) = ________________ and A = ____ (constant)

b) It follows that f(x) = (-4 sqrt(9x**2 + 6) / (-6x-8) = (A’ sqrt(p(x)) / (-6-8/x)

find p(x) and A’

c) what is the limit?

d) Now find as x goes to – infinity (exact same information, but with – infinity.)

my work has gotten some of these (in class we didn't use the same format webwork expects..)

f(x) = (-4 sqrt(9x**2 + 6) / (-6x-8)

i took the sqrt(x**2 ) out and got (-4 sqrt(9+ 6/x**2) / (-6-8/x)

For the constant part of filling it in, -4 doesn't work for "A" and neither does - 12 (thought mauybe -4 * sqrt9)

anyway i found the limit as x goes to infinity which is 2.

considering i don't know what they want for the value of A, which is a constant, i don't know what they want for A'

I tired using teh value 0, (derivative of a constant) but that is wrong!

hope somoene can help me out on this A thing they're wanting of me!!!

thankyou

Brittany