Final answer:
The electric flux through a square can be calculated by finding the dot product of the electric field with the normal vector to the square. We can use the given angles to determine the electric flux at each angle.
Step-by-step explanation:
To find the electric flux through the square, we need to calculate the dot product of the electric field with the normal vector to the square. The electric flux through a surface is given by the equation ∃ˆ·dA, where ∃ˆ is the electric field and dA is the differential area vector. In this case, the electric field is given as D = x²yz⃓⃑‹x + x⃒⃓⃓⃑y + cos⃓⃓⃓z. The normal vector to the square is defined by the angles it makes with the electric field. We can then use the given angles (30°, 90°, and 0°) to calculate the electric flux through the square at each angle.