<p>Blue Book Page 426 # 14
if (a + b)^1/2 = (a - b)^-1/2, which of the following must be true?
A) b = 0
b) a + b = 1
c) a - b = 1
d) a^2 + b^2 = 1
e) a^2 - b^2 = 1</p>
<p>Answer is E. Can anyone explain how to arrive at the answer?</p>
<p>bump - can anyone help me out?</p>
<p>< will represent the square root sign (because I can't find anything else closer)</p>
<p>(a + b)^1/2 = (a - b)^-1/2
<(a + b) = 1/(<(a - b))
<((a + b)(a - b)) = 1
Square both sides and factor.
a^2 - b^2 = 1</p>
<p>I think that's how you do it. Let me know if that doesn't make sense.</p>