Explain the likely behaviour of total product and marginal product when only one input is increased while all other inputs are kept unchanged.
it have 3 phases which is also called law of variable propotion
in 1st phase total product[TP] increases at an increasing rate and marginal product[MP] also increases
in 2nd phase TP increase at an diminishing rate and MP decreases but remains +ve
in 3rd phase ultimately TP falls and MP also falss that it becomes -ve