A sequence of numbers u_1, u_2, …, u_n, … is given by the formula where n is a positive integer.

(a) Find the value of u_1, u_2 and u_3.

(b) Show that to 4 s.f.

(c) Proved that .

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(a) u_1 = 1, u_2 = 1/3 & u_3 = -1/9.

How could I do rest of them?