Given the complex numbers z1 = 22i and z2 = 1+i, find z4 1 and z1/z2 by using the polar form. Compare the results with those you get by means of the Cartesian form of the complex numbers.

(a) An arithmetic sequence {an} has a first term a1 = 15 and difference d = 8. Find the term a101.

(b) For an arithmetic sequence, the terms a8 = 21 and a10 = 25 are known. Find difference d and the terms a1 and an.