That number is called "i", the imaginary unit. The name "imaginary" is for historical reasons; these numbers have many practical applications, for example in electricity.
The square root of -1 is "i". However engineers use "j", but it's essentially the same thing.
There are mathematical concepts that mathematicians call "imaginary numbers" these are a multiple of the square root of minus 1. Infinity is not a real number either.
Because as a prime number it is very boring.
Pringles
Mathematicians decided that, since the square root of a negative number does not exist, they would use the first letter of "imaginary" to represent this "value".
Two, multiplied by the square root of negative one. (2i) The square root of negative 1 is purely imaginary, but mathematicians don't have much else to be imaginative about.
10 mathematicians.
Yes
The lower case ' i ' is the symbol for ' square root of -1 '. 'i' = sqrt(-1) 'i' refers to IMAGINARY numbers. Reason, mathematicians have been researching for an answer to the sqrt(-1) for many years, and still have no answer!!!!!
1 is not a prime number because it can be evenly divided by itself and by 1, the opposite as per the definition of a prime number.
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Square root ( 1) = +/-1 Remember -1 X -1 = (+)1 +1 x +1 = (+)1 So the square root of (+)1 can be either (+)1 or (-)1 However, do NOT confuse with the 'square root (-1)' . Mathematicians for centuries have been pondering over this problem, and still no answer!!!!!