Options:
A) $ \sqrt{2} $
B)1
C) $ \sqrt{3} $
D)2
Show Answer
Answer:
Correct Answer: D
Solution:
- The given lines are $ \pm x\pm y=1 $ i.e. $ x+y=1,x-y=1,x+y=-1 $ and $ x-y=-1 $ These lines form a quadrilateral whose vertices are $ A(-1,0),B(0,-1),C(1,0) $ and $ D(0,1) $ Obviously ABCD is a square. Length of each side of this square is $ \sqrt{1^{2}+1^{2}}=\sqrt{2} $ Hence area of square is $ \sqrt{2}\times \sqrt{2}=2sq. $ unitsTrick: Required area = $ \frac{2c^{2}}{|ab|}=\frac{2\times 1^{2}}{|1\times 1|}=2 $ .