Complex Numbers Multiplication
The complex numbers obey the commutative, associative, and distributive laws. But although the property =
dose not hold for complex numbers in general, it does hold when a = -1 and b is a positive real number.
To multiply square roots of negative real numbers, we first express them in terms if i .
For example,
.
=
.
.
.
= i
. i
= i2 = –
is correct!
But .
=
=
is wrong!
Keeping this and the fact that i2 = -1 in mind, we multiply in much the same way that we do with real numbers.