The second and fifth terms of a geometric series are 750 and -6 respectively. Find: (1) the common ratio; (2) the first term of the series; (3) the sum to infinity of the series
xn = ar(n-1)(1) x2 = 750 = ar1(2) x5 = -6 = ar4divide second equation by first-6/750 = r3r3 = -0.008r= -0.2Insert into first equation.750 = a * -0.2a = -3750Sum to infinite series = a(1/(1-r))(insert known variables)Sum to infinite series = -3750 * 1/1.2= -3125
HP
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