Plz help me with the following:

1. Use pascal's triangle to determine the first four terms of (e^x - e^-x)^12

2. Determine the first four terms in the expansion of: root(1 + x/2) and indicate limitations. Leave coeficient in simple fractional form.
3. Use the binomial expansion to evaluate: root 26 to five decimal places.
Hint: Express 26 as 5^2 + 1

4. determine the ninth term of (x - 1/x^1/2)^12