9. * Consider the function f(x) = x cos(x) and the integral I = So f(x)dr. If the Maclaurin series of f(x) is used to approximately calculate I, determine the minimum number of non- zero terms of the series that need to be used so that the error in calculating I is below 0.1%? With this minimum number of terms, what is the percentage error? (For this question, the answer to the percentage error can be in decimal form.)