l lx 4 1):4 00 = Z x" for le

4 xn for IXI < I to expand the function in a power series with center c = O. Use the equation (Express numbers in exact form. Use symbolic notation and fractions where needed.) 4 Determine the interval of convergence. (Give your answer as an interval in the form (*,*). Use the symbol 00 for infinity, U for combining intervals, and an appropriate type of parenthesis ( , ) , [ , ] depending on whether the interval is open or closed. Enter if the interval is empty. Express numbers in exact form. Use symbolic notation and fractions where needed.)