1. Find the lim x goes to 4 on the postive side of the function x-5/(4-x^3)(x-7)^2.

2. Find the lim x goes to postive Pi/2 of the function tan x.

3. Find the lim x goes to infinity (2x+1)/x^2-(2x-1)/x^2.

4. Find the lim x goes to infinity (x^2)/(2x+1) - (x^2)/(2x-1)

5. Fiind the lim x goes to infinity x^3/3^x