Let a function defined on the set of all real numbers satisfy
and
Consider the region enclosed by the curve , the line
and the two vertical lines and .The area of this region is equal to
for some rational numbers .Find the value of .oindent
The problem asks for the area of the region enclosed by the curve , the line , and the vertical lines and .
First, I derived the expression for on the interval . Given , we have . For , let . Then . Thus, . Since , we use the base definition . So, .
Let . As goes from to , goes from to . The functions in terms of are: Curve: Line:
The area is given by .
The problem states . So I need to compute and express it in the form .
I will use Python to compute this integral symbolically.
[PYTHON] from sympy import symbols, sin, pi, integrate, Abs, sqrt, simplify
t = symbols('t', real=True)
Define the integrand part without the absolute value
expr = t * (2 * sin(pi * t) - 1)
Determine where 2sin(pit) - 1 is positive/negative in [0, 1]
sin(pit) = 1/2 at pit = pi/6 and 5*pi/6 => t = 1/6 and 5/6
In [0, 1/6], sin(pi*t) < 1/2, so expression is negative.
In [1/6, 5/6], sin(pi*t) > 1/2, so expression is positive.
In [5/6, 1], sin(pi*t) < 1/2, so expression is negative.
Split the integral
I1 = integrate(-expr, (t, 0, 1/6)) I2 = integrate(expr, (t, 1/6, 5/6)) I3 = integrate(-expr, (t, 5/6, 1))
total_integral = simplify(I1 + I2 + I3) print(total_integral) [/PYTHON]
[THOUGHT] The previous output used floating point numbers for fractions, leading to an inexact representation. I need to re-compute the integral using exact rational arithmetic in SymPy to match the form .
The integral is . Splitting the domain based on where changes sign:
- :
- :
- :
So .
I will compute this exactly. [/THOUGHT] [PYTHON] from sympy import symbols, sin, pi, integrate, Rational, sqrt, simplify
t = symbols('t')
Define the integrand parts
Region 1: [0, 1/6], integrand is t - 2tsin(pit)
term1 = t - 2tsin(pi*t) I1 = integrate(term1, (t, 0, Rational(1, 6)))
Region 2: [1/6, 5/6], integrand is 2tsin(pit) - t
term2 = 2tsin(pi*t) - t I2 = integrate(term2, (t, Rational(1, 6), Rational(5, 6)))
Region 3: [5/6, 1], integrand is t - 2tsin(pit)
term3 = t - 2tsin(pi*t) I3 = integrate(term3, (t, Rational(5, 6), 1))
total_integral = simplify(I1 + I2 + I3) print(total_integral) [/PYTHON]
The area of the region is given by the integral of the absolute difference between the curve and the line over the interval . Let . The interval becomes . The function is and the line is . The area is:
Using Python, we computed the integral and found:
Comparing this to the form , we identify:
We are asked to find the value of :