Let a function defined on the set of all real numbers satisfyandConsider the region enclosed by the curve , the line and the two vertical lines and .The area of this region is equal tofor some rational numbers .Find the value of 2028 $$\cdot$$ p $$\cdot$$ q $$\cdot$$ r.oindent
[THOUGHT] To solve this problem, we need to find the area of the region enclosed by the curve ( y = f(x) ), the line ( y = 2^{1012}(x - 2026) ), and the vertical lines ( x = 2026 ) and ( x = 2027 ).
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Understand the function ( f(x) ):
- For ( x \in [0, 2] ), ( f(x) = x \sin(\pi x) ).
- For other ( x ), ( f(x) = 2 f(x-2) ). This means ( f(x) ) is defined recursively, scaling by 2 every 2 units.
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Find ( f(x) ) for ( x \in [2026, 2027] ):
- Since ( f(x) ) is defined recursively, we can express ( f(x) ) in terms of ( f(x - 2k) ) where ( x - 2k \in [0, 2] ).
- For ( x \in [2026, 2027] ), let ( x = 2026 + t ) where ( t \in [0, 1] ).
- Then, ( x - 2 \times 1013 = 2026 + t - 2026 = t ), so ( f(x) = 2^{1013} f(t) = 2^{1013} t \sin(\pi t) ).
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Set up the integral for the area:
- The area is the integral of the difference between the line and the curve from ( x = 2026 ) to ( x = 2027 ).
- The line is ( y = 2^{1012}(x - 2026) = 2^{1012} t ) (where ( t = x - 2026 )).
- The curve is ( y = 2^{1013} t \sin(\pi t) ).
- The difference is ( 2^{1012} t - 2^{1013} t \sin(\pi t) = 2^{1012} t (1 - 2 \sin(\pi t)) ).
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Compute the integral:
- The area ( A ) is: [ A = \int_{0}^{1} 2^{1012} t (1 - 2 \sin(\pi t)) , dt ]
- This can be split into two integrals: [ A = 2^{1012} \left( \int_{0}^{1} t , dt - 2 \int_{0}^{1} t \sin(\pi t) , dt \right) ]
- The first integral is straightforward: [ \int_{0}^{1} t , dt = \frac{1}{2} ]
- The second integral requires integration by parts: [ \int t \sin(\pi t) , dt = -\frac{t \cos(\pi t)}{\pi} + \frac{\sin(\pi t)}{\pi^2} + C ] Evaluating from 0 to 1: [ \left. -\frac{t \cos(\pi t)}{\pi} + \frac{\sin(\pi t)}{\pi^2} \right|_{0}^{1} = -\frac{\cos(\pi)}{\pi} + \frac{\sin(\pi)}{\pi^2} - 0 = \frac{1}{\pi} ]
- Thus: [ A = 2^{1012} \left( \frac{1}{2} - 2 \cdot \frac{1}{\pi} \right) = 2^{1012} \left( \frac{1}{2} - \frac{2}{\pi} \right) ]
- However, the problem states the area is of the form ( 2^{1012} \left( p + \frac{q}{\pi} + \frac{r \sqrt{3}}{\pi} \right) ). Comparing, we see ( p = \frac{1}{2} ), ( q = -2 ), and ( r = 0 ).
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Compute ( 2028 \cdot p \cdot q \cdot r ):
- Since ( r = 0 ), the product ( 2028 \cdot p \cdot q \cdot r = 0 ).
[/THOUGHT] [PYTHON]
Verify the integral calculations
from sympy import symbols, integrate, sin, pi
t = symbols('t') integral1 = integrate(t, (t, 0, 1)) # Should be 1/2 integral2 = integrate(t * sin(pi * t), (t, 0, 1)) # Should be 1/pi
print(integral1, integral2) [/PYTHON]
[THOUGHT] The Python output confirms the integral calculations:
- (\int_{0}^{1} t , dt = \frac{1}{2})
- (\int_{0}^{1} t \sin(\pi t) , dt = \frac{1}{\pi})
Thus, the area is: [ A = 2^{1012} \left( \frac{1}{2} - \frac{2}{\pi} \right) ] This matches the form (2^{1012} \left( p + \frac{q}{\pi} + \frac{r \sqrt{3}}{\pi} \right)) with (p = \frac{1}{2}), (q = -2), and (r = 0). Therefore, (2028 \cdot p \cdot q \cdot r = 0).
[/THOUGHT] \boxed{0}