Please walk me through this problem!

.2 - or - 8 1. [4 marks] Consider the function p(a) = where a is constant. x2 - 3x - 4 (a) Find the value a such the lim p(x) may exist (i.e. evaluate to a finite number). Do not try to evaluate the limit. [Hint: r'-3x -4 -0 as r -> 4, so the only way lim p(x) may exist is if a- -ar - 8 approaches what value as r -> 4? (b) Evaluate, if possible, lim p(x) using the value determined in part (a) for a