how can i do this w/out plugging in?
a>b>0, then (a^2-b^2)^1/2
oa [spoiler](a+b)^1/2*(a-b)^1/2[/spoiler]
a>b>0, then (a^2-b^2)^1/2
oa [spoiler](a+b)^1/2*(a-b)^1/2[/spoiler]
This is a common thing to see on the GMAT. You need to know that:
(a^2-b^2) = (a+b)(a-b)
So, in this problem, you're taking the original expression to the 1/2 power. You can convert into the second expression, and "distribute" that 1/2 to both terms to get:
(a+b)^1/2 x (a-b)^1/2
It's MUCH easier to do this without typing (i.e., on a blackboard) - I hope that makes sense!
I never have gotten used to using the ^ character for exponents. It makes my brain freeze up. I edited my previous post for clarity's sake.
