Let z = rei be a nonzero complex number and n a negative integer (n = 1, 2, . . .). Then define z1/n by

Let z = reiθ be a nonzero complex number and n a negative integer (n = −1, −2, . . .). Then define z1/n by means of the equation z1/n = (z−1)1/m where m = −n. By showing that the m values of (z1/m)−1 and (z−1)1/m are the same, verify that z1/n = (z1/m)−1.