Please help me understand these questions

EXERCISES 4.1 Show that the differential equation solution given in Equation [4.5), y = CH?" A" + (Eelx, is completely equivalent to the solution in Equation (4.6}. _v = D1 eosfx} + D: sink/Ex). and expire-59: C. and C3 in terms of Di and 03. If both D. and D; are real and nonzero. is it possible for both C. and C3 to be real"? 4.2 Show that the general expression for the wave function for a free particle. given by Equation [4.3l as 'PEJ. I} = Cw\"\"'"'\" + Cgef\""""\"'\". is not an eigenfunction of momentum unless C] = t] or C3 = U