i need an explanation to the underlined answers pls (check attached picture)

i got different answer for the first one

i got : e^(lny+y)-e^y=y

thnx

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- Oct 13th 2009, 10:28 AMalex83its a solved integration
i need an explanation to the underlined answers pls (check attached picture)

i got different answer for the first one

i got : e^(lny+y)-e^y=y

thnx - Nov 7th 2009, 10:45 AMMoo
Hello,

Strange that no one replied to this...

$\displaystyle [e^{x+y}]_0^{\ln(y)}=e^{\ln(y)+y}-e^{0+y}=e^{\ln(y)}e^y-e^y=ye^y-e^y=(y-1)e^y$

then they just performed an integration by parts :)