Q. Let $d _1\left(\left( x _1, y _1\right),\left( x _2, y _2\right)\right)=\left| x _1- x _2\right|+\left| y _1- y _2\right|$ and $d _2\left(\left( x _1, y _1\right),\left( x _2, y _2\right)\right)=\sqrt{\left( x _1- x _2\right)^2+\left( y _1- y _2\right)^2}$ denote the distance between $\left(x_1, y_1\right)$ and $\left(x_2, y_2\right)$ on the coordinate plane. The area of the region enclosed by the set of points ( $x, y)$ satisfying $d_1((x, y),(0,0)) \geq 1$ and $d_2((x, y),(0,0)) \leq 1$, is
Application of Integrals
Solution:
Clearly required area $=$ Area of circle - Area of square $=\pi-(\sqrt{2})^2=\pi-2$ (square units)
