So I have this seemingly simple, but I just don't see how this works?
please if you can solve this, explain every step that leads to the result.
pretty nasty eh? Or maybe I'm just stupid
There are two typos in your problem.
I don't see where that "2" comes from.
Also, you left out the square-root in the second expression.
How we get from: .
. . . to: .
Under the radical, we have: .
Multiply the second term by
. . .
Take the square root: . .
Substitute into the original expression:
I think I got it, the square root disappears because I can do a Binomial Approximation which states:
Therefore solving the two missing "2"s you were saying. Am i correct?
P.S. This was part of a physics problem I have (Solid State Physics), which the algebra was kind of horrible to solve as you can see from the above...