The area of the region R = \(x, y) : xy 8, 1 y x2, x 0\ is
- 23(20 e(2) + 9)
- 13(40 e(2) + 27)
- 13(49 e(2) - 15)
- 23(24 e(2) - 7)
Answer
(4) 23(24 e(2) - 7)
Solution
[figure]
Region: y 1, to the right of y = x2 (i.e. x y) and to the left of xy = 8 (i.e. x 8y).
Curves meet where x2 = 8x x = 2, y = 4
y varies from 1 to 4 (horizontal strips)
Area = 14 ( 8y - y )dy
= [8 e y - 23y3/2 ]14
= 8 e 4 - 23(8 - 1)
= 16 e 2 - 143
= 23(24 e(2) - 7)
Answer: (4)