L'Hopitals Rule with derivatives?

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The discussion focuses on evaluating the limit lim x--> 0 (4^x - e^2x) / (2x) using L'Hôpital's Rule. Participants clarify the derivatives involved: the derivative of 4^x is 4^x * ln(4) and the derivative of -e^2x is -2e^2x. The correct application of the chain rule is emphasized, particularly rewriting 4^x as e^(x ln(4)). This approach leads to a clearer path for solving the limit without confusion over the derivatives.

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Question is:
Evaluate the following limits
lim x--> 0 4^x - e^2x / 2x
So i take derivatives
but that's where I am confused... Whats the derivate of 4^x... x4^-x?
and is the derivative of -e^2x -2e^x?
So then that leaves me with 4x^-x -2e^x /2which is 0... so do i do derivatives again? It seems like the x's won't go away?
 
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You can use the chain rule and the fact that the derivative of e^x is e^x to answer both questions. That is, the derivative of e^f(x) is e^f(x)*f'(x). Try to rewrite 4^x as e^f(x). (use logs)
 
[tex]f(x)=4^x[/tex]
[tex]\ln(f(x))=x\ln(4)[/tex]
[tex]\frac{1}{f(x)}*f'(x)=\ln(4)[/tex]

You can take it from there.
 

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