How do you find the Integral of sqrt(x^2 - 16)/ x dx?

1 Answer
Oct 26, 2015

Using the trigonometric substitution technique of integration we eventually get
int(sqrt(x^2-16))/xdx=sqrt(x^2-16)-4sec^(-1)(x/4)+C

Explanation:

I will use the trigonometric substitution technique of integration to solve this integral.

Let u=4 sec theta
therefore du = 4 sectheta tantheta d theta

Therefore the original integral becomes :

int (sqrt(4^2sec^2 theta - 4^2))/(4sectheta)*4sec theta tan theta d theta

=int sqrt(4^2(sec^2 theta - 1))/(4sectheta)*4sec theta tan theta d theta

=int 4 tan^2 theta d theta

=4 (tan theta - theta) + C

=(sqrt(x^2-16))-4sec^(-1)(x/4)+C