Christmas MT's answer to Geraldine's Secondary 4 A Maths question.

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Christmas MT
Christmas Mt's answer
3275 answers (A Helpful Person)
If you are confused as to why the two are always positive, remember that e is positive, and no matter what x is, you can never make a positive number negative by "power-ing" it.
e^(-2) is simply to put e into the denominator;
e^(1/2) is simply the square root.
Moreover, the two e's are summed together, not minused, so there is no way it can ever give 0.

Furthermore, there is no x value where you can make 2e^x or e^(-2x) equals to zero. Remember, e^0 = 1.

So, f'(x) is always > 0, meaning it can never be 0 :)