SOLUTION: Hi, Please help me with this one: If {{{ (a + b)^.5 = (a - b)^-.5 }}}, which of the following must be true? The exponent is actually 1/2 (not .5), I just didn't know how to inp

Algebra ->  Matrices-and-determiminant -> SOLUTION: Hi, Please help me with this one: If {{{ (a + b)^.5 = (a - b)^-.5 }}}, which of the following must be true? The exponent is actually 1/2 (not .5), I just didn't know how to inp      Log On


   



Question 83881: Hi, Please help me with this one:
If +%28a+%2B+b%29%5E.5+=+%28a+-+b%29%5E-.5+, which of the following must be true? The exponent is actually 1/2 (not .5), I just didn't know how to input it using the plot formula. The answer is +a%5E2+-+b%5E2+=+1+ but I don't know why. Thanks!

Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
If +%28a+%2B+b%29%5E.5+=+%28a+-+b%29%5E-.5+, which of the following must be true?
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Rewrite as:
sqrt(a+b) = 1/sqrt(a-b)
Cross-mutiply to get:
sqrt(a^2-b^2)=1
Square both sides to get:
a^2-b^2 = 1
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Cheers,
Stan H.