9-9 Supplemental problems In Exercises 1- 4. find the interval of convergence and the function of x represented by the geometric series. 1. 2"x" 2. E (-1)" ( x + 1)" n=0 1= 0 3 . = ( -2 ) " ( x - 3) " 4. 3 x - 1) 1=0 2 5-8: For each problem 1-4, use the series and the function f(x) that it represents to find a power series for f (x). 9-12: For each problem 1-4, use the series centered at a and the function it represents to find a power series for Saf(t) dt