<p>5.) 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>Multiply both sides by (a-b)^1/2 and you get [(a+b)(a-b)]^1/2 = (a-b)^0.</p>
<p>Recall that: (any number)^0 = 1, and that (a+b)(a-b) = (a^2 - b^2). Substitute above and square both sides. You get a^2 - b^2 = 1.</p>