Area of the region {(x,y)∈R2:y≥∣x+3∣,5y≤x+9≤15} is equal to
(A)61
(B)34
(C)23✓ Correct
(D)35
Answer: (C)
Solution
Shift the origin to (−3,0) to get the region {(x,y):y≥∣x∣,5y≤x+6≤15}. The region is bounded by y=∣x∣, x+6=5y (i.e., y=5x+6), and x+6=15 (i.e., x=9). The area can be computed by breaking it into regions and integrating. The total area works out to 38+1+31−25=23.
JEE Advanced · 2016 · 22 May 2016 · Paper 2 · Single correct option