A trough of water is 20 meters long and its ends are in the shape of an isosceles triangle
whose width is 7 meters and height is 10 meters. Assume that the two equal length sides of the
triangle are the sides of the water tank and the other side of the triangle is the top of the tank and
is parallel to the ground. Water is being pumped into the tank at a rate of 2 m3/min. When the
water is 6 meters deep at what rate is (a) depth changing and (b) the width of the top of the water
changing?

Question

A trough of water is 20 meters long and its ends are in the shape of an isosceles triangle
whose width is 7 meters and height is 10 meters. Assume that the two equal length sides of the
triangle are the sides of the water tank and the other side of the triangle is the top of the tank and
is parallel to the ground. Water is being pumped into the tank at a rate of 2 m3/min. When the
water is 6 meters deep at what rate is (a) depth changing and (b) the width of the top of the water
changing?