If the length of a tangent from any point on the circle :

Question

is (x-3)² +(y+2)² =5r² to the circle (x-3)² + (y+2)² =r² is 16 unit ,then the area between the two circles in sq. unit is : 

• 32pi
•  8pi
•  4pi 
• 256pi 
• 16pi

Answer 1

Let point P(x₁,y₁) be any point on the circle, therefore it satisfy the circle  

(x₁−3)²+(y₁+2)²=5r² ...(i) 

The length of the tangent drawn from point P(x1,y1) to the circle