Unformatted text preview: square root of a
negative number down to the square root of a positive number (which we or a calculator can deal
with) times -1 . -1 we could actually deal with square roots of negative
numbers. Well the reality is that, at this level, there just isn’t any way to deal with -1 so
So, if we just had a way to deal with instead of dealing with it we will “make it go away” so to speak by using the following definition. i = -1
Note that if we square both sides of this we get, i 2 = -1
It will be important to remember this later on. This shows that, in some way, i is the only
“number” that we can square and get a negative value.
Using this definition all the square roots above become, -9 = 3 i -100 = 10 i -5 = 5 i -290 = 290 i These are all examples of complex numbers.
The natural question at this point is probably just why do we care about this? The answer is that,
as we will see in the next chapter, sometimes we will run across the square roots of negative
© 2007 Paul Dawkins 52 http://tutorial.math.lamar.edu/terms...
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This note was uploaded on 06/06/2012 for the course ICT 4 taught by Professor Mrvinh during the Spring '12 term at Hanoi University of Technology.
- Spring '12