({3e}^{2x} - {e}^{-x})({e}^{x} + {3e}^{-2x})

Need help with the above equation ... Remove brackets and simplify expontential expression !!!

I got a result of .... after simplifying .... 8e ... i hope its correct ..

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- Apr 28th 2011, 02:15 AMdaemonliesSimplify expression
({3e}^{2x} - {e}^{-x})({e}^{x} + {3e}^{-2x})

Need help with the above equation ... Remove brackets and simplify expontential expression !!!

I got a result of .... after simplifying .... 8e ... i hope its correct .. - Apr 28th 2011, 02:59 AMtopsquark
- Apr 28th 2011, 04:19 AMSorobanQuote:

Originally Posted by**topsquark**

Dan is correct . . . but**how far**should we simplify?

http://latex.codecogs.com/png.latex?... 1}{9^xe^{3x}}

- Apr 28th 2011, 06:01 AMbjhopper
Hi Dan,

Isn't the middle term of the posted function equal to 1 ?

bjh - Apr 28th 2011, 06:17 AMtopsquark
- Apr 28th 2011, 08:05 AMbjhopper
Hi Dan,

Thanks for your reply.I did not remove brackets properly and was getting one term in the middle of the other two =1 when I should gotten two terms +1 and -1.

bjh - Apr 28th 2011, 02:07 PMdaemonlies
This is what i got .....

(3e^2x - e^(-x) )(e^x+3e^(-2x) )

3e^3x + 9e - e - 3e^(-3x)

Cancelled out 3e^3x & - 3e^(-3x)

9e - e = 8e - Apr 28th 2011, 02:18 PMtopsquark
The original problem as written was stated in terms of . In this last post you wrote . Which was it supposed to be?

Otherwise recall the general rule

Let's first talk about the

by the rule I just mentioned. e^0 = 1, not e.

Similarly

Finally

I'd recommend you review your exponent rules.

-Dan

Edit: If your problem really is

then the answer is

See if you can get that with what we showed you in this thread. - Apr 28th 2011, 03:55 PMdaemonlies
the edit section is the correct equation ... but wouldnt 3e^3x - e^-3x = 2e .... being the powers cancel out so ... 3e -e = 2e

Joel