Please ignore the mention of p in question 3  - it is irrelevant


Note that the function in problem 5 can be described piecewise as

f(x) = 1+4x^2  for x<0
f(x) = 1       for x>0

Integrals therefore need to be split into two.




Note that problem 2b can be done in more than one way.
It is an exercise in algebra (or calculus) - nothing more advanced.