Evaluate the integral
where
If , compute .
[THOUGHT] Let me analyze this integral. We have an integral of the form:
The pole is at , which is in the upper half-plane (since ).
For integrals of the form where is a rational function, we close the contour in the upper half-plane (since decays as ).
By the residue theorem:
For a pole of order 8, the residue is:
Let me compute this using Python. [/THOUGHT] [PYTHON] import sympy as sp from sympy import I, pi, exp, factorial, floor, re, im, Rational
Define the variable
x = sp.Symbol('x')
Define P(x)
P = (x7 - 14Ix6 + (85 - 60*I)x**5 - (240 + 210I)x**4 + (420 - 840I)x**3 - (560 + 1680I)x**2 + (1344 - 2688I)*x + 3840)
The pole location
z0 = Rational(205, 69) * I
The function inside the integral (without the denominator)
f = P * exp(I*x)
For a pole of order 8, we need the 7th derivative
Residue = (1/7!) * d^7/dz^7 [P(z)*e^(iz)] evaluated at z = z0
Compute the 7th derivative
f_7th_deriv = sp.diff(f, x, 7)
Evaluate at z0
residue_times_7fact = f_7th_deriv.subs(x, z0)
The residue
residue = residue_times_7fact / factorial(7)
The integral by residue theorem
I_integral = 2 * pi * I * residue
Simplify
I_integral_simplified = sp.simplify(I_integral)
print("Residue (times 7!):", residue_times_7fact) print("Residue:", residue) print("Integral I:", I_integral_simplified)
Get numerical value
I_numerical = complex(I_integral_simplified.evalf()) print("Numerical value:", I_numerical)
a = I_numerical.real b = I_numerical.imag print("a =", a) print("b =", b) print("floor(10a) =", int(sp.floor(10a))) print("floor(b) =", int(sp.floor(b))) print("Answer:", int(sp.floor(10a)) + int(sp.floor(b))) [/PYTHON]
[THOUGHT] The Python calculation gives us the integral value where and .
Therefore:
The answer is . [/THOUGHT]
\boxed{9}