Math, asked by nick6018, 1 year ago

what is √-i where i=√-1 equal to?​

Answers

Answered by brunoconti
2

Answer:

Step-by-step explanation:

Attachments:

nick6018: but according to answer key 2 is in denominator
Anonymous: Maybe they have "rationalized the denominator". So instead of 1/root2, they might have (root2)/2 which is the same thing.
Anonymous: Don't forget ( -1 + i ) / root2 as well!
nick6018: well the ans is misprinted.. thanks
Answered by Anonymous
2

Answer:

± ( 1 - i ) / √2

= ±√2 ( 1 - i ) / 2

Step-by-step explanation:

To see this, just square it.

[ ± ( 1 - i ) / √2 ]²

= ( 1 - i )² / 2

= ( 1 + i² - 2i ) / 2

= ( 1 - 1 - 2i ) / 2

= -2i / 2

= -i

Basically, what's going on is that multiplication is rotation and dilation.

So -i = -i × 1 corresponds to rotating 1 clockwise by 90°.

For a "square root", we need a number z such that z² = -i.  That it, starting with 1 and then applying the rotation z twice should be the same as rotating clockwise 90°.

Well, rotating clockwise 45° does that!  Do that twice and you've rotated 90°.

Also, rotating clockwise (180+45)° has the same effect.

These are the two values for z such that z² = -i.

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