I am having trouble with Q5 in the attached file,

For part (a) after expanding and simplifying I have the answer:

f(z)=(36x^2)+4iBy-12ix

How would I wite the real and imaginary parts of the function in terms of B, x and y?

Also for which values of B is f differentiable? and where?....

...... Btw is there a program of some sort I can download to write up the questions in a more 'mathematical way' so I can write the symbols, instead of attaching the files?? Thanks