Question

Find the product of z1 and z2 where z1 = 7(cos 40° + i sin 40°), and z2 = 6(cos 145° + i sin 145°).

42(cos 40° + i sin 40°)

42(cos 185° + i sin 185°)

13(cos 185° + i sin 185°)

42(cos 5800° + i sin 5800°)

Answer 1

multiply \(7\times 6=42\)
add \(40+145=185\) that is all

Answer 2

42(cos 185° + i sin 185°)

Answer 3

yup