Prove f is integrable using six subintervals and evaluate.

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SUMMARY

The function f defined as f(x) = 2 for 0 ≤ x < 1, f(1) = 0, f(x) = -1 for 1 < x < 2, f(2) = 3, f(x) = 0 for 2 < x < 3, and f(3) = 1 is proven to be integrable using six subintervals. The partition P = {0, 1-h, 1+h, 2-h, 2+h, 3-h, 3} is utilized, where 0 < h < 1/2. The sum S_P is calculated as S_P = 2(1-h) + 2(2h) + (-1)(1-2h) + 3(2h) + 0(1-2h) + h = 2 + 9h. The goal is to show that the integral ∫f(x) dx equals 1 by proving that J < 1 + ε.

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Homework Statement


Define f as: f(x)= 2 if 0\leqx<1
f(1)=0
f(x)= -1 if 1<x<2
f(2)= 3
f(x)=0 if 2<x<3
f(3)=1
Prove f is integrable using six subintervals and find the value of \intf(x) dx


The Attempt at a Solution


Let P={0, 1-h, 1+h, 2-h, 2+h, 3-h, 3} where 0<h<1/2
I just need help proving \intf(x) dx=1.
I can prove I\geq1, but I'm having trouble proving J<1+\epsilon
I have S_{P}=2(1-h)+2(2h)+(-1)(1-2h)+3(2h)+0(1-2h)+h= 2+9h
but now I don't know how to get that to less than 1+\epsilon
 
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gotmilk04 said:

Homework Statement


Define f as: f(x)= 2 if 0\leqx<1
f(1)=0
f(x)= -1 if 1<x<2
f(2)= 3
f(x)=0 if 2<x<3
f(3)=1
Prove f is integrable using six subintervals and find the value of \intf(x) dx


The Attempt at a Solution


Let P={0, 1-h, 1+h, 2-h, 2+h, 3-h, 3} where 0<h<1/2
I would split the interval up this way:
P = {0, 1 - h, 1, 1 + h, 2 - h, 2, 3}

I'm basically ignoring the discontinuities at 2 and 3, since they aren't going to contribute anything to the integral.
gotmilk04 said:
I just need help proving \intf(x) dx=1.
I can prove I\geq1, but I'm having trouble proving J<1+\epsilon
I have S_{P}=2(1-h)+2(2h)+(-1)(1-2h)+3(2h)+0(1-2h)+h= 2+9h
but now I don't know how to get that to less than 1+\epsilon
 

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