Saturday, 11 May 2019

calculus - Calculate a limit of exponential function



Calculate this limit:



limx=(15+15x)x5



I did this:




(15)x5[(1+1x)x]15



(15)x5(55)15



(15)x5(15)55



limx=(15)x+55



limx=(15)=0




Now I checked on Wolfram Alpha and the limit is 1
What did I do wrong? is this the right approach? is there an easier way?:)



Edit:
Can someone please show me the correct way for solving this? thanks.



Thanks


Answer



The limit is indeed 0, but your solution is wrong.

limx(15+15x)x/5=5limx(15)xlimx(1+1x)x=50e=0



And WolframAlpha confirms it: https://www.wolframalpha.com/input/?i=%281%2F5%2B1%2F%285x%29%29%5E%28x%2F5%29+as+x-%3Einfty


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