Question

integral of 7/(8x + 1) from 0 to 6

Answer 1

\[\int\limits_{0}^{6} \frac{7}{8x+1}\]

Answer 2

u = 8x + 1
du = 8dx
1/8 du = dx

\[7/8 \int\limits_{0}^{6} \frac{du}{u}\]

Answer 3

\[\ln|u| \] for 0 to 6

Answer 4

now the issue I'm having is that 7/8[ln(6) - ln(0)] should be infinity, however when I plug it into wolfman It gives me a different answer...

http://www.wolframalpha.com/input/?i=integral+of+7%2F%288x+%2B+1%29+from+0+to+6

Answer 5

what am i doing wrong?

Answer 6

all you did wrong is to forget to change your limits of integration...
it's not from 0 to 6 anymore

Answer 7

oh yeah I forgot, I usually turn it back into x :P.

Answer 8

:)

Answer 9

(ln((8 * 6) + 1) - (ln(1)) which is log(49)

Answer 10

* 7/8 = 7log(49)/8

Answer 11

or 2ln(7)

Answer 12

stupid mistake thanks :).

Answer 13

yw...:)