Understanding Complex Numbers in Dot Product Calculations

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robertjford80
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Homework Statement


Worked solution showing the length of the vector with entries 1+i and 3: square root of the inner product with itself, then sqrt((1-i)(1+i) + (3)(3)) = sqrt(1 - i^2 + 9) = sqrt(11).







The Attempt at a Solution



do you see where it sees sqrt((1-i)(1+i)+9)?

It should be (1+i)(1+i)

Why isn't it?
 
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hi robertjford80! :smile:
robertjford80 said:
do you see where it sees sqrt((1-i)(1+i)+9)?

It should be (1+i)(1+i)

Why isn't it?

the complex inner product is defined with a conjugate on one side …

<a|b> = a*.b

(for real vectors, it makes no difference, so this isn't a different definition, it's the same as for real vectors :wink:)