Michigan State University - Diagnostic Exam

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4.4

  •   Let √ --- i = - 1 . After expanding and simplifying, (4 + i)3 =

    a) 64 + i3 b) 64 - i c) 28 + 53i
       
    d) 52 + 47i e) 60 + 15i

Solution:

=43+3(42)i + 3(4)i2 + i3 = 64 + 48i - 12 - i = 52 + 47i

Diagnostic:

See 4.3: Complex Numbers and 4.16: Binomial Theorem .

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July 15, 2008