Consider the quadratic equation 2t2+(k−3)t+(k+5)=0, where k is a real parameter.
(i) Write the expression for the discriminant of the equation.
(ii) Determine the set of values of k for which the equation has two distinct real roots.
(iii) Find the value(s) of k for which the equation has equal real roots.
(iv) For what values of k does the equation have no real roots? Justify your answer.