The given expression is equal to:
cos((π/12) * (7π/12)) = cos(π^2 / 12) = cos(π^2 / 12) = cos(π^2 / 12) = cos(π/2) = 0
Therefore, cos(π/12) cos(7π/12) - sin(π/12) sin(7π/12) = 0.
The given expression is equal to:
cos((π/12) * (7π/12)) = cos(π^2 / 12) = cos(π^2 / 12) = cos(π^2 / 12) = cos(π/2) = 0
Therefore, cos(π/12) cos(7π/12) - sin(π/12) sin(7π/12) = 0.