For \( \sin^{-1}(y) \) to be valid, \( y \) must lie between -1 and 1.
Therefore, the expression \( 2x - 1 \) must lie between -1 and 1: \[ -1 \leq 2x - 1 \leq 1 \] Solving this inequality: \[ 0 \leq x \leq 1 \] Thus, the domain is \( [0, 1] \).
Let \[ f(t)=\int \left(\frac{1-\sin(\log_e t)}{1-\cos(\log_e t)}\right)dt,\; t>1. \] If $f(e^{\pi/2})=-e^{\pi/2}$ and $f(e^{\pi/4})=\alpha e^{\pi/4}$, then $\alpha$ equals