Integral of hyperbolic function

[DryRun]

Homework Statement
\int^4_3 \frac{1}{\sqrt{3x^2-6x+1}}\,.dx

The attempt at a solution
I complete the square for the quadratic:
\sqrt{3x^2-6x+1}<br /> \\=\sqrt{3(x^2-2x+\frac{1}{3})}<br /> \\=\sqrt 3 \times \sqrt{(x-1)^2-\frac{2}{3}}
\int^4_3 \frac{1}{\sqrt{3x^2-6x+1}}\,.dx<br /> \\=\frac{1}{\sqrt 3}\int^4_3 \frac{1}{\sqrt{(x-1)^2-\frac{2}{3}}}\,.dx<br /> \\=\frac{1}{\sqrt 3} \left[\cosh^{-1}\frac{\sqrt 3(x-1)}{\sqrt 2}\right]^{x=4}_{x=3}<br /> \\=\frac{1}{\sqrt 3} \left[\cosh^{-1}\frac{3\sqrt 3}{\sqrt 2}-\cosh^{-1}\sqrt 6\right]
I already simplified it but it doesn't agree with the final answer:
\frac{1}{\sqrt 3}\ln \left(\frac{15+\sqrt {219}}{12+\sqrt {138}}\right)

 

[tiny-tim]

hi sharks!

cosh^-1x = ln(e^cosh-1x)

= ln(cosh(cosh^-1x) + sinh(cosh^-1x))

= ln (x + √(x² - 1)) ​

 

[DryRun]

Hi tiny-tim

The above expression is what i used to expand:
\frac{1}{\sqrt 3} \left [\cosh^{-1}\frac{3\sqrt 3}{\sqrt 2}-\cosh^{-1}\sqrt 6\right]<br /> \\=\frac{1}{\sqrt 3} \ln \left[\frac {3\sqrt 3+5}{\sqrt{12}+\sqrt{10}}\right]=0.4625025064
But if i evaluate the answer from my notes, i get:
\frac{1}{\sqrt 3}\ln \left (\frac{15+\sqrt {219}}{12+\sqrt {138}}\right)=0.1310541888
Since the answers are not the same, I'm thinking that maybe the answer in my notes is wrong?

 

[tiny-tim]

well that's obviously …
\frac{1}{\sqrt 3} \left[\cosh^{-1}\frac{\sqrt 3(x+1)}{\sqrt 2}\right]^{x=4}_{x=3}

… either the question or the answer is wrong