Step 5 Now we must finde radius of convergence for the Maclaurin series First we set up the ratio test as follows 4 n 2 x 1 an 1 lim 816 an lim 510 Submit Skip you cannot come back n o 4 n 1 x That is the positive number R such that the series converges if x al R and diverges if Ix al R We can use the ratio test to find R