The total product curve in (a)shows the output produced for different amounts of labor input.The average and marginal products in (b)can be obtained(using the data in Table 6.2)from the total product curve. At point A,the marginal product is 20 because the tangent() to the total product curve has a slope of 20.At point B in (a)the average product of labor is 20,which is the slope of the line from the origin(原点，origin of coordinates)toB.The total product curve in (a) shows the output produced for different amounts of labor input. The average and marginal products in (b) can be obtained(using the data in Table 6.2)from the total product curve. At point A, the marginal product is 20 because the tangent(切线) to the total product curve has a slope of 20. At point B in (a) the average product of labor is 20, which is the slope of the line from the origin (原点, origin of coordinates) to B