Matrix Calculation Error: Finding the Correct Solution

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SoggyBottoms
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Homework Statement



See attached image.

The Attempt at a Solution



I get a different solution: First multiply by [itex]\sqrt{2}[/itex], then [itex]{1 \choose -1} = {c + d \choose ci - di}[/itex]. So we get [itex]c + d = 1[/itex] and so [itex](1 - d)i - di = -1[/itex]. Solving the last one gives [itex]2di = 1 + i[/itex], so [itex]d = \frac{1 + i}{2i} = \frac{1 + i}{2i}\frac{i}{i} = \frac{i - 1}{-2} = \frac{1 - i}{2}[/itex]. But that's the answer for c. Where does my solution go wrong?
 
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  • Equations: chi' = c chi_+^(y) + d chi_-^(y); equivalent to (1/sqrt 2)(1, -1) = (c/sqrt 2)(1, i) + (d/sqrt 2)(1, -i); c = (1 - i)/2; d = (1 + i)/2.
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The book is wrong. You can see this by substituting their "solution" into the original equation.