A 5-meter ladder is sliding down a vertical wall so the distance between the bottom of the ladder and the wall is increasing at 6 meters per minute.At a certain instant, the top of the ladder is 3 meters from the ground.What is the rate of change of the area formed by the ladder at that instant (in square meters per minute)?Choose 1 answer:(A) 6(B) −14(C) 18(D) −7
Q. A 5-meter ladder is sliding down a vertical wall so the distance between the bottom of the ladder and the wall is increasing at 6 meters per minute.At a certain instant, the top of the ladder is 3 meters from the ground.What is the rate of change of the area formed by the ladder at that instant (in square meters per minute)?Choose 1 answer:(A) 6(B) −14(C) 18(D) −7
Form Right Triangle: The ladder, wall, and ground form a right triangle. The ladder is the hypotenuse, and the distance from the wall is one leg, which is increasing at 6 meters per minute. The other leg is the height from the ground to the top of the ladder, which is 3 meters.
Calculate Area: Let's call the distance from the wall to the bottom of the ladder x meters. The area A of the triangle formed by the ladder, wall, and ground is (21)×x×3.
Differentiate Area: Differentiate the area with respect to time to find the rate of change of the area, dtdA. dtdA=21×3×dtdx.
Find Rate of Change: We know dtdx, the rate at which the bottom of the ladder moves away from the wall, is 6 meters per minute. So, dtdA=21×3×6.
Calculate dtdA: Calculate dtdA: dtdA=(21)×3×6=3×6=18 square meters per minute.
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