# Math Help - infinite series

1. ## infinite series

Consider the infinite series of the form:
(+/-)3(+/-)1(+/-)(1/3)(+/-)(1/9)(+/-)(1/27)(+/-)...(+/-)(1/3^n)(+/-)...

(A) Find x and y from: x(</=)(+/-)3(+/-)1(+/-)(1/3)(+/-)...(</=)y.
(B) Can you choose the signs to make the series diverge?
(C) Can you choose the signs to make the series sum to 3.5?
(D)Can you choose the signs to make the series sum to 2.25?
(E) Can you choose the signs to make the series sum to (159/36)?

For (C), can you make 3 and 1 both positive and then the rest of the series negative, which would be a negative geometric series? A little shaky on that.

And for (D), is that an alternating series?

2. How do you do (A)?