calculus
posted by Jane on .
Help  I have three problems that I am stuck on 
1. Lim x approaches infinity
(x3/x squared + 4)
2. Lim x approaches 3
x cubed  x squared  7 x +3/
x squared  9
3. Lim x approaches negative infinity
(x + square root x squared + 2x)

1. You need to use more parentheses to clarify the mathematical operation. I will assume you mean
1. Lim x > infinity
(x3)/(x^2 + 4)
When x approaches infinity, you can neglect the constant terms, and you get
Lim x > infinity
(x/x^2) = 1/x
As x> infinity, that approaches zero.