Math 3
Notes 7-4
Multiplicative Inverses and Division of Complex Numbers
The multiplicative identity for Real numbers is 1.
The multiplicative identity for Complex Numbers is 1 + 0i.
Recall our study of irrational numbers:
We could not leave an answer with a radical in the denominator, so
we needed to rationalize the denominator:
ex. Express each of the following with rational denominators:
The same principle applies to complex numbers: we can never leave an
answer with 'i' in the denominator.
Ex. 3 Divide and simplify:
Ex. 4 Divide and simplify:
Ex. 5 Divide and simplify:
Ex. 6 Write the multiplicative inverse of 2 + 4i in a + bi form.
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Ex. 7 Given: 3 - 4i, find (in a + bi form):
a. the additive inverse ____________
b. the conjugate ____________
c. the multiplicative inverse _____________
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Solving Quadratic Equations with imaginary roots
Ex. 8 Solve for x and express your answer in simplest a + bi form:
Ex. 9 Solve for x and express your answer in simplest a + bi form:
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