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How is



?
Original post by Banny Dyrne
How is



?


e2=1e2 e^{-2} = \frac{1}{e^{2}} . Same thing for e4 e^{-4}

So

e2e42=(1e21e4)12 \frac{e^{-2} - e^{-4}}{2} = \left(\frac{1}{e^2} - \frac{1}{e^4} \right) \cdot \frac{1}{2}

Multiply top and bottom of 1e2 \frac{1}{e^2} by e2 e^2 (to get a common denominator)

(e2e2e2=e41e4)12 \left( \frac{e^2}{e^2 \cdot e^2 = e^4} - \frac{1}{e^4} \right) \cdot \frac{1}{2}

e21e412=e212e4 \frac{e^2 - 1}{e^4} \cdot \frac{1}{2} =\frac{e^2 - 1}{2e^4}



EDIT: Why did I get negged?
(edited 11 years ago)
Reply 2
Original post by Banny Dyrne
How is



?


Just multiply numerator and denominator of LHS by e4e^4
Reply 3
Oh ok. Is it necessary to do this simplification though?
Reply 4
Original post by Banny Dyrne
Oh ok. Is it necessary to do this simplification though?


necessary for what?
Reply 5
Original post by Banny Dyrne
Oh ok. Is it necessary to do this simplification though?


Not really but the RHS looks prettier.
Original post by Banny Dyrne
How is



?

using the facts that:
x*1=x
and e4e4=1 \frac{e^4}{e^4} = 1
you should be able to do it.

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