integrate (5^x)(e^x) dx I cannot figure out this one...please help
U Unco Senior Member Joined Jul 21, 2005 Messages 1,134 Feb 3, 2006 #2 How about rewriting: \(\displaystyle \L\mbox{ 5^x = \left(e^{\ln{(5)}}\right)^x = e^{\left(x\ln{(5)}\right)}}\)
How about rewriting: \(\displaystyle \L\mbox{ 5^x = \left(e^{\ln{(5)}}\right)^x = e^{\left(x\ln{(5)}\right)}}\)
pka Elite Member Joined Jan 29, 2005 Messages 11,976 Feb 3, 2006 #4 In general \(\displaystyle \L \int {a^x dx = \frac{{a^x }}{{\ln (a)}}\mbox{ if }\ a > 0}\) Also recall that \(\displaystyle \L \left( {5^x } \right)\left( {e^x } \right) = \left( {5e} \right)^x\) So let \(\displaystyle \L a = 5e.\)
In general \(\displaystyle \L \int {a^x dx = \frac{{a^x }}{{\ln (a)}}\mbox{ if }\ a > 0}\) Also recall that \(\displaystyle \L \left( {5^x } \right)\left( {e^x } \right) = \left( {5e} \right)^x\) So let \(\displaystyle \L a = 5e.\)
U Unco Senior Member Joined Jul 21, 2005 Messages 1,134 Feb 3, 2006 #5 Then the integrand can be written \(\displaystyle \mbox{ e^{\left(x(\ln{(5)} + 1)\right)}}\). And I'm sure you can integrate \(\displaystyle \mbox{e^{ax}}\).
Then the integrand can be written \(\displaystyle \mbox{ e^{\left(x(\ln{(5)} + 1)\right)}}\). And I'm sure you can integrate \(\displaystyle \mbox{e^{ax}}\).