Question

Use the formula to evaluate the infinite series riund to the nearest hundredth if necessary 9+3+1+

Answer 1

Sum to infinity  =  a1 / ( 1 - r)   (This is a geometric series  a1 = first term, r = common ratio)

Here r = 3/9  = 1/3 and a1 = 9 

So the answer is 9 / (1 - 1/3)  = 9 / 2/3 = 9 * 3/2 = 13.5 Answer