This one is testing your knowledge of imperfect roots.
Just plug in the numbers.
A. sqroot of 1 is one. Eliminate.
B. sqroot of 2 is 1.4, which will give you a positive number. Eliminate.
C. sqroot of 3 is 1.7, which will give you a positive number. Eliminate.
D. sqroot of 4 is 2, which will give you a positive number. Eliminate.
E. sqroot of 5 is 2.2 which will leave you with a sqroot of 2 - 2.2, which is - 0.8 which is going to give you some result with i (i = -1). Not a real number. E is your answer.
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AleksandrM
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Good summary from Aleksander ... this question is checking your understanding of square roots of negative numbers.
You cannot have a square root of a negative number ... a square root of a negative number is known as an "imaginary number", since no real number exists which when squared will give a negative number.
You cannot have a square root of a negative number ... a square root of a negative number is known as an "imaginary number", since no real number exists which when squared will give a negative number.
