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| why in this question is not possible the following when c is the answer if r=1/2 then r^2=1/2^2=1/4 then lrl = to -1/2 (since from an absolute value we have positive and negative ) then result = 1/4>-1/2 . I understand when r=-1/2 then r^2=-1/2^2 = 1/4 and lrl=1/2 then this gives us 1/4<1/2 |
A variable inside an absolute value does mean that the variable could be positive or negative, but you start your question by saying "if r = 1/2" - so you've just set that variable to be positive 1/2, not negative 1/2. You have to keep using that value for r throughout the problem once you set it.