Before converting it directly into , look at it in terms of cos and sin:
You can simplify it more and it'll be easier to integrate.
1. The problem statement, all variables and given/known data
integral√(9-x²) / (x²)
2. Relevant equations
Just trig substitution
3. The attempt at a solution
Ok, for trig sub I did
u=asinΘ
x=3sinΘ
9-x²=9-9sin²=9(1-sin²Θ)
so putting it into the equation
x²=9sin²Θ
dx=3cosΘ
√9cos²Θ=3cosΘ/x^2
(3cosΘ/9sin²Θ)*(3cosΘ)=9cos²Θ/9sin²Θ= cot²
but the integral of cot is ln(sinU) or it can be -ln(cscu)
I am stuck