Let the line x = -1 divide the area of the region \(x, y) : 1 + x2 y 3 - x \ in the ratio m : n, (m, n) = 1. Then m + n is equal to
- 27
- 28
- 25
- 26
Answer
(1) 27
Solution
Intersection: 1 + x2 = 3 - x x2 + x - 2 = 0 x = -2, 1
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Let F(x) = (2 - x - x2) dx = 2x - x22 - x33
F(-2) = -4 - 2 + 83 = - 103, F(-1) = -2 - 12 + 13 = - 136, F(1) = 2 - 12 - 13 = 76
A1 = F(-1) - F(-2) = - 136 + 206 = 76
A2 = F(1) - F(-1) = 76 + 136 = 206
A1 : A2 = 7 : 20, (7, 20) = 1
m + n = 7 + 20 = 27
Answer: (1)