I solved an integral using trig sub

the answer I got was $\displaystyle \sqrt{x^2-9} - 3 sec^{-1} \frac{x}{3} + C$

I checked my answer on wolfram it gave $\displaystyle \sqrt{x^2-9} + 3tan^{-1} \frac{3}{\sqrt{x^2-9} }$

I understand the 3 and sqrt{x^2-9}. My problems is, shouldn't it be $\displaystyle -3tan^{-1} \frac{\sqrt{x^2-9}}{3}$?