For each of the following production functions calculate the marginal product

with respect to each factor, the marginal rate of technical substitution and graph the coresponding isoquants. Evaluate whether the marginal product of each factor is increasing,

constant or decreasing (over any relevant ranges). Evaluate whether the returns to scale.

1. f (K, L)=2K +L

2. f (k, L)= min{2K, K + L}

3. f (k, L)= K + min{K, L}

4. f (K, L)= max{K,2L}