mr fantastic MHF Hall of Fame Dec 2007 16,948 6,768 Zeitgeist May 8, 2010 #2 TsAmE said: Find a function f such that f(1) = 0 and f'(x) = 2^(x) / x Click to expand... \(\displaystyle f(x) = \int_1^x \frac{2^t}{t} \, dt\). Reactions: General and skeeter

TsAmE said: Find a function f such that f(1) = 0 and f'(x) = 2^(x) / x Click to expand... \(\displaystyle f(x) = \int_1^x \frac{2^t}{t} \, dt\).

skeeter MHF Helper Jun 2008 16,216 6,764 North Texas May 8, 2010 #3 mr fantastic said: \(\displaystyle f(x) = \int_1^x \frac{2^t}{t} \, dt\). Click to expand... I love it when it's simple ... (Clapping)

mr fantastic said: \(\displaystyle f(x) = \int_1^x \frac{2^t}{t} \, dt\). Click to expand... I love it when it's simple ... (Clapping)

T TsAmE Apr 2010 58 0 May 9, 2010 #4 Arent you suppose to find the anti-derivative of f'(x) = 2^(x) / x?

mr fantastic MHF Hall of Fame Dec 2007 16,948 6,768 Zeitgeist May 9, 2010 #5 TsAmE said: Arent you suppose to find the anti-derivative of f'(x) = 2^(x) / x? Click to expand... In that case, good luck ....

TsAmE said: Arent you suppose to find the anti-derivative of f'(x) = 2^(x) / x? Click to expand... In that case, good luck ....

T TsAmE Apr 2010 58 0 May 10, 2010 #6 mr fantastic said: In that case, good luck .... Click to expand... I am not sure of the method you used, thats why I asked, as I thought that the only of finding it was by using an anti-derivative

mr fantastic said: In that case, good luck .... Click to expand... I am not sure of the method you used, thats why I asked, as I thought that the only of finding it was by using an anti-derivative

General Jan 2010 564 242 Kuwait May 10, 2010 #7 Mr F did not use any method .. He get the answer by using the FTC .. The problem here is that \(\displaystyle \int \frac{2^x}{x} \, dx\) is unelementary integral .. What ever you do, you can not evaluate it in terms of elementary functions .. Reactions: mr fantastic

Mr F did not use any method .. He get the answer by using the FTC .. The problem here is that \(\displaystyle \int \frac{2^x}{x} \, dx\) is unelementary integral .. What ever you do, you can not evaluate it in terms of elementary functions ..