If \( \alpha + \beta + \gamma = 2\pi \), then the system of equations
\( x + (\cos \gamma) y + (\cos \beta) z = 0 \)
\( (\cos \gamma) x + y + (\cos \alpha) z = 0 \)
\( (\cos \beta) x + (\cos \alpha) y + z = 0 \)
Let \( [\lambda] \) be the greatest integer less than or equal to \( \lambda \). The set of all values of \( \lambda \) for which the system of linear equations \( x + y + z = 4 \), \( 3x + 2y + 5z = 3 \), \( 9x + 4y + (28 + [\lambda])z = [\lambda] \) has a solution is :
