Evaluate 4 si$n^2$ 60° + 3 ta$n^2$ 30° - 2 co$s^2$ 45°.

Substitute the standard values one term at a time. sin 60° = √(3)/2, so si$n^2$ 60 = 3/4 and $4\times 3/4=3$. tan 30° = 1/√(3), so ta$n^2$ 30 = 1/3 and $3\times 1/3=1$. cos 45° = 1/√(2), so co$s^2$ 45 = 1/2 and $2\times 1/2=1$. The expression is 3 + 1 - 1 = 3. The trap 2 comes from using si$n^2$ 60 = 1/2 (that is co$s^2$ 60 or si$n^2$ 45, not si$n^2$ 60). The trap 4 drops the last term, treating co$s^2$ 45 as 0. The trap 5 uses ta$n^2$ 30 = 1, which is ta$n^{2}45$.