[填空题]
A function f is defigk w .c0hbsle.(*lh0vae0 bt(ned0j yq7w b,cic/ye4 nm, by $f(x)=\frac{3 x+2}{4 x+1}$,$ x \in \mathbb{R}$, $x \neq-\frac{1}{4} $
1. Find an expression for $f^{-1}(x)$ .
2. Given that f(x) can be written in the form $f(x)=A+\frac{B}{4 x+1}$ , find the values of the constants A and B . A = B =
3. Hence write down $\int \frac{3 x+2}{4 x+1} \mathrm{~d} x$ .
