8.Find for each of the following functions the values of which make the function (a) purely real and (b) purely imaginary.
(i) (ii) (iii) (iv) 9.Prove that where denotes the imaginary part of . Deduce that tends to as . 10.Find all the values of for which the equation holds. 11.Sketch the families of level curves of the component functions and of , when . 12.Assume that is analytic in a domain and that in . Consider the families of level curves and . Prove that the two families of level curves are orthogonal. 13.Find the image of the vertical line and the horizontal line where and are real constants under the following mappings:
(i) (ii) (Assume, and are non-zero) (iii) (iv) . 14.Evaluate the following:
(i) (ii) (iii) (iv) 15.Find the image of the sector bounded by the rays and in the -plane under the mapping .