The curve is given parametrically by x=ektcost and y=ektsint, where k is a real constant and t takes all real values. Answer the following questions:
a. (i) Derive an expression for dx2d2y in terms of k and t.
b. (ii) Determine the condition on k for which dx2d2y>0 for every real t.
c. (iii) For the value(s) of k obtained in part (ii), verify that the curve possesses no points of inflection.