I have 2 calculus questions that are giving me trouble and would love some help.

#1 To which of the following does the integral x/ sqrt. x^2 - 1 dx

reduce after an appropriate trig. substitution?

1. Integral sec^2 (x) dx
2. Integral sin^2 (x) dx
3. Integral tan(x) sec^2(x) dx
4. Integral tan^2(x) dx
5. Integral sin^2(x) sec(x) dx
6. Integral sin(x) sec^2 (x) dx

#2 Determine the integral 6/ (x sqrt. x^2 + 9 dx)

• the numerator of the above integral is 6
• the denominator of the above integral is x sqrt. x^2 + 9