(a) Show that w = z has the values (b) Obtain from (18) the often more practical formula where sign y = 1 if y

(a) Show that w = ˆšz has the values

(b) Obtain from (18) the often more practical formula

where sign y = 1 if y ‰¥ 0, sign y = -1 if y < 0, and all square roots of positive numbers are taken with positive sign. Use (10) in App. A3.1 with x = θ/2.

(c) Find the square roots of -14i, -9 - 40i, and 1 + ˆš48i by both (18) and (19) and comment on the work involved.

+ i sin W1 cos Vr cos (18) W2 = Vr | cos + T+i sin = -W1. (19) Vz = [V4(z| + x) + (sign y)i V(|z| + x)]