What's wrong with my approach???

Quadratic equations and inequalities, variation equations, function notation, systems of equations, etc.
monjinho
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What's wrong with my approach???

Postby monjinho » Wed Sep 07, 2011 8:29 am

With the problem 2/(1-i) * (1+i)/(1+i),

since (1+i)/(1+i) cancels out to a one, if you multiply one times 2/(1-i), don't you just get 2(1-i)??
For some reason, the answer is l+i.
Why can't you just make (1+i)/(1+i) equal one?

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stapel_eliz
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Re: What's wrong with my approach???

Postby stapel_eliz » Wed Sep 07, 2011 11:08 am

monjinho wrote:...if you multiply one times 2/(1-i), don't you just get 2(1-i)??

How are you getting that dividing by 1 - i is the same as multiplying by 1 - i?

Instead, try rationalizing the denominator. Don't cancel first; multiply out the denominator. What do you get? :wink:


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