Let \( f:\mathbb{R}\to\mathbb{R} \) be defined asWhere \( [x] \) is the greatest integer less than or equal to \( x \). If \( f \) is continuous at \( x=2 \), then \( \lambda+\mu \) is equal to:
\( 1 \)
\( e(-e+1) \)
\( 2e-1 \)
\( e(e-2) \)