Are Individual Functions Riemann Integrable if Their Sum is?

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SUMMARY

In the discussion, it is established that if the sum of two bounded functions \( f \) and \( g \) on the interval \([a,b]\) is Riemann integrable, it does not necessarily imply that both \( f \) and \( g \) are Riemann integrable. A counterexample is provided where \( f(x) = 1 \) for irrational \( x \) and \( f(x) = 0 \) for rational \( x \), demonstrating that \( f \) is not Riemann integrable while \( g = 1 - f \) can be integrable.

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losin
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suppose f and g are bounded functions on [a,b] such that f+g is in R[a,b]

Then, does it follow that f and g are also in R[a,b]? i wanto to prove whether it is or not
 
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Not so. Let f be a function which is NOT Riemann integrable and let g=1-f.

For example f(x)=1, when x is irrational and f(x)= 0, when x is rational.
 

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