The area of the region \(x, y) : 0 y 6-x, . . y2 4x-3, x 0 \ is :
- 8
- 9
- 12
- 15
Answer
(2) 9
Solution
[figure]
y2 4x-3 x y2+34 (left of the parabola, vertex ( 34, 0 ))
Meeting point with x+y=6 : y2=4(6-y)-3 y2+4y-21=0
(y+7)(y-3)=0 y=3 (as y 0), x=3
For 0 y 3 the right boundary is the parabola; for 3 y 6 it is the line x=6-y
Area = 03 y2+34dy+ 36(6-y) dy
= 14 [ y33+3y ]03+ [6y- y22 ]36
= 14(9+9)+ (18- 272 )
= 92+ 92=9
Answer: (2)