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6. (a) Show that all positive eigenvalues of the boundary value problem below must be in the form 1 = o', where o satisfies the equation o = 3cot(on). X" +xX= 0, X' ( 0 ) = 0 and 3X(TC ) + X'( TC) = 0. (b) Show that 1 = 0 is not an eigenvalue of this boundary value