Hi.

(Let, Int=integral and Sqrt=square root and In=natural log)

In a math book I found that

Int( Sqrt(Z^2-A^2) )

= (A^2)/2 * ( (Z*Sqrt(Z^2-A^2))/(A^2) - In((Z+sqrt(z^2-A^2))/A) )

= (Z*Sqrt(Z^2-A^2))/2 - ( (A^2)/2 * In((Z+sqrt(z^2-A^2))/A) )

but with my TI-89 titanium calculator the same integral gave

Int( Sqrt(Z^2-A^2) )

= (Z*Sqrt(Z^2-A^2))/2 - ( (A^2)/2 * In(Z+sqrt(z^2-A^2)) )

After some working out on paper, I found my calculator gave the wrong result. I not too sure why this is. Can anyone tell me which is correct ?

Thanks