Two workers at the Meta Headquarters in Menlo Park, California need to work closely on a project. Each worker =1,2 chooses simultaneously (and independently) an amount of effort ≥0 (measured in hours of work per day) to invest on the project. The effort is costly, but there are synergies between the two workers. The value to each worker from effort levels (₁,₂) is ₁+2₂+₁₂. Worker 1's cost of effort is 1/51/2 and worker 2's cost of effort is 22/2.
Write down the normal form of this game.