autodidude
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I'm trying to differentiate e^x from first principles but I can't find a way to manipulate this expression \frac{e^h-1}{h} so I can evaluate the limit without getting 0/0
The discussion revolves around evaluating the limit as h approaches 0 of the expression (e^h - 1)/h, particularly in the context of differentiating e^x from first principles. Participants explore various methods to handle the limit, including definitions of e and L'Hôpital's rule.
Participants express differing views on the appropriateness of using L'Hôpital's rule in this context, with some arguing against it while others support its use. The discussion remains unresolved regarding the best approach to evaluate the limit.
Some participants highlight the potential for circular logic when applying L'Hôpital's rule without first establishing the derivative of e^x. The discussion also reflects uncertainty about how to manipulate the expression to avoid the 0/0 indeterminate form.
Diffy said:
Diffy said:
eumyang said:Use the definition of e:
lim_{h \rightarrow 0} \left( 1 + h \right)^{1/h} = e
So for small values of h,
e \approx \left( 1 + h \right)^{1/h}, or
e^h \approx 1 + h.
Replace eh in \frac{e^h-1}{h} with 1 + h and go on from there.
Um, you need to simplify the expression.autodidude said:Don't we get 0/0 again?
Limit h->0
\frac{1+h-1}{h}