## mpj4 one year ago isn't the integral of dx / [x (7x^2 - 5)^(1/2) ] = 1/a arcsec u/a??

1. mpj4

I ask because I applied it and I got it wrong.

2. mpj4

3. ganeshie8

looks you forgot to put the absolute value bars

4. mpj4

maybe

5. mpj4

my solution

6. mpj4

forgot to square the a=5 and the integral signs. Sorry, was a bit hasty making it.

7. Michele_Laino

you can try this substitution: $\large \sqrt {7{x^2} - 5} = \sqrt 7 x + t$ where t is the new variable of integration

8. mpj4

Ok, thanks!