Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Applications of Derivatives

Question:
The length x of a rectangle is decreasing at the rate of 2 cm/minute and the width y is decreasing at the rate of 3 cm/minute. When x =2 cm and y = 2 cm, which of the following statements hold true?
Options:
The area of the rectangle increases at the rate of 10 cm2/min.
The area of the rectangle decreases at the rate of 10 cm2/min.
The area of the rectangle changes at the rate of 0 cm2/min.
No definite results
Correct Answer:
The area of the rectangle decreases at the rate of 10 cm2/min.
Explanation:
dA/dt = -3x-2y