Are Individual Functions Riemann Integrable if Their Sum is?

In summary, the Riemann integral problem is a mathematical concept used to find the area under a curve on a given interval. It is different from other types of integrals because it uses a partitioning method to approximate the area. The Riemann integral problem is important in various fields and has two conditions that must be met for a function to be Riemann integrable. It is solved using the Riemann sum formula by choosing a partition, calculating the area of each subinterval, and taking the limit as the number of subintervals increases.
  • #1
losin
12
0
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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  • #2
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.
 

FAQ: Are Individual Functions Riemann Integrable if Their Sum is?

What is the Riemann integral problem?

The Riemann integral problem is a mathematical concept that involves finding the area under a curve on a given interval. It is named after the mathematician Bernhard Riemann and is a fundamental concept in calculus.

How is the Riemann integral problem different from other types of integrals?

The Riemann integral problem is different from other types of integrals, such as the Lebesgue integral, because it uses a partitioning method to approximate the area under the curve. This involves dividing the interval into smaller subintervals and calculating the area of each one.

What is the importance of the Riemann integral problem?

The Riemann integral problem is important because it allows us to calculate the area under a curve, which has many practical applications in fields such as physics, engineering, and economics. It also serves as the basis for other integral concepts and techniques.

What are the conditions for a function to be Riemann integrable?

A function must satisfy two conditions to be Riemann integrable: it must be bounded (meaning its values do not exceed a certain threshold) and it must be continuous (meaning it has no abrupt changes in value).

How is the Riemann integral problem solved?

The Riemann integral problem is solved by using a specific formula, called the Riemann sum, to approximate the area under the curve. This involves choosing a partition of the interval, calculating the area of each subinterval, and then taking the limit as the number of subintervals approaches infinity.

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