SOLUTION: what is the square root of 4 over 5 but not in decimal form?

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Question 256651: what is the square root of 4 over 5 but not in decimal form?
Answer by drk(1908) About Me  (Show Source):
You can put this solution on YOUR website!
Here is the question:
sqrt%28+4+%2F+5%29
We are allowed to split the sqrt as
sqrt%284%29+%2F+sqrt%285%29
Now sqrt(4) = 2, so , we get
2%2Fsqrt%285%29
but we don't like sqrt's in the denominator, so, we rationalize by multiplying by sqrt(5) on top and bottom as
%282%2Asqrt%285%29%29 / sqrt%285%29%2Asqrt%285%29%29
and then
2sqrt%285%29%2F5