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The value of the integral
∞∫-∞ sin x dx is x² + 2x + 2
evaluated using contour integration and the residue theorem is
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πsin (1) e -
- πcos (1) e -
sin (1) e -
cos (1) e
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Correct Option: A
| I = ∞∫-∞ | ||
| x² + 2x + 2 |
| let f(x) = | ||
| z² + 2z + 2 |
Then poles of f(z) are given by z² + 2z + 2 = 0
∴ z = – 1 ± i
R1 = Res: (f(z): z = -1 + i)
| Ltz→-1±1[z-(-1+i)] | ||
| [z-(-1+1)][z-(-1-i)] |
| = | = | ||
| -1 + i + 1 + i | 2i |

| = IM[πe-1(cos(1) - isin(1))] = - | ||
| e |