Question

Let z1= 2+3i, z2=2-3i, and z3= 4+5i find:
z1z2

Answer 1

does that mean multiply ?

Answer 2

YAA but complex multiplication but keep 1 thing in mind i^2=-1

Answer 3

ie i=sqrt(-1)

Answer 4

i=sqrt(-1) always like that or ?

Answer 5

always it is iota it appears when there is negative sign inside sqrt
likesqrt(-4)=sqrt(4)sqrt(-1)=2i

Answer 6

so answer is 65

Answer 7

cuz i^2=-1

Answer 8

i mean 13

Answer 9

what r u finding???

Answer 10

opps 65 was the problem number my bad lol

Answer 11

Note that this is zz', where z' is the conjugate, so the answer should be a real number. 13 is right.

Answer 12

yes 13

Answer 13

yeah my bad lol

Answer 14

In general, zz' = |z|^2 :-)

Answer 15

ok thanks bmp ^^