[ 6-6642 - op net sinds 10.1.15-(E)-17.10.2026 ]
Translation in E N G L I S H
|
A. 1 |
| B. e |
| C. 0 |
D.  |
| E. ∞ |
Oplossing - Solution
Denkend aan ab = eb.ln a kunnen we schrijven :
\(\displaystyle\lim_{\underset{>}{x\to 0}}\;(\cot x)^x=\lim_{\underset{>}{x\to 0}}\:e^{x.\ln(\cot x)}\overset{stel}{=}\lim_{\underset{>}{x\to 0}}e^{EXPO}\)
We gaan nu die exponent berekenen :
\(\displaystyle\lim_{\underset{>}{x\to0}}\:{EXPO}=\lim_{\underset{>}{x\to0}}\:x.\ln(\cot x)=\lim_{\underset{>}{x\to0}}\:\frac{\ln(\cot x)}{\frac1x}\left(=\frac{+\infty}{+\infty}\right)\\\buildrel H\over=\displaystyle\lim_{\underset{>}{x\to0}}\:\frac{\frac{1}{\cos x}.\left(-\frac{1}{\sin^2x}\right)}{-\frac{1}{x^2}}=\lim_{\underset{>}{x\to0}}\:\left(\frac{1}{\cot x}.\frac{x}{\sin x}.\frac{x}{\sin x}\right)=\frac{1}{+\infty}.1.1=_{(+)}0\)
De gevraagde limiet is dus gelijk aan e0 = 1
