Struggling with another question.

$\displaystyle f(x)= sinh^-1 (5x)$

Then i went to this

$\displaystyle f'(x)= 5 (1/(1-5(x))^2)$

Not sure what to do after that.

Thanks in advance

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- May 31st 2009, 08:45 AMjamm89Another second derivatives question. :(
Struggling with another question.

$\displaystyle f(x)= sinh^-1 (5x)$

Then i went to this

$\displaystyle f'(x)= 5 (1/(1-5(x))^2)$

Not sure what to do after that.

Thanks in advance - May 31st 2009, 10:06 AMAmer
ok

$\displaystyle f(x)=sinh^{-1}(5x) $

$\displaystyle f'(x)= \frac{(5x)'}{1+(5x)^2}=\frac{5}{1+25x^2}=5(1+25x^2 )^{-1}$

$\displaystyle f''(x)= this..... for..... you....

$ - May 31st 2009, 11:19 AMjamm89
$\displaystyle f''(x)= -5 (50x) (1+25x^2)^-2$

Is that correct for the second derivatives?

Cheers - May 31st 2009, 11:37 AMAmer
Yeah it is correct (Rofl)