**Complex Numbers Multiplication**

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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

= i^{2} = – is correct!

But . = = is wrong!

Keeping this and the fact that i^{2} = -1 in mind, we multiply in much the same way that we do with real numbers.