Target Exam

CUET

Subject

Maths. Section B1

Chapter

Applications of Derivatives

Question:

An architect designs a garden in a circular shape with centre E and radius 50 m. There is a flower bed ABCD of rectangular shape inside the garden as shown in the figure. Suppose length and width of the flower bed are 2x and 2y meters respectively.

Based on above information answer the following question:

If area of the flower bed is maximum, then area (in m2) of garden, which is outside the flower bed is:

Options:

1250 (π - 2) m2

1250 (π + 2) m2

2500 (π - 2) m2

2500 (π + 2) m2

Correct Answer:

2500 (π - 2) m2

Explanation:

The correct answer is Option 3: 2500 (π - 2) m2

Radius (r)=50

Area of circle (Garden) = $= πr^2$ = 50x50xπ =2500π

Maximum Flower Bed: Occurs when the rectangle is a square.

Diagonal =diameter=100 m.

Side of square (s) = 100 / $\sqrt{2}$ = $50\sqrt{2}$

Area of square = $s^2$ = $50\sqrt{2}$ x $50\sqrt{2}$ =5,000

Outside Area: 2500π5000 = 2500(π2m2