Figure 1 shows the curve = ! and a point (−1,0). The point (, 0) is a variable point on the axis and increases at a rate of 10 units "#. The line is parallel to the axis.
a) Express the area of PQR in terms of .
b) Calculate the rate of change in the area when = 2.
c) Calculate the rate of change in the length when = 1.

Figure 1

Luke started a weight-loss program. the first week, he lost x pounds. the second week, he lost pounds less than times the pounds he lost the first week. the third week, he lost 1 pound more than of the pounds he lost the first week. liam started a weight-loss program when luke did. the first week, he lost 1 pound less than times the pounds luke lost the first week. the second week, he lost 4 pounds less than times the pounds luke lost the first week. the third week, he lost pound more than times the pounds luke lost the first week.