True or False Integral Calculus Question #3

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Discussion Overview

The discussion revolves around a true or false question regarding the behavior of right-hand Riemann sums for the integral of the square of a negative function that is increasing on the interval [0, 1]. Participants explore whether these sums yield an underestimate or an overestimate of the integral.

Discussion Character

  • Debate/contested

Main Points Raised

  • One participant suggests that right-hand Riemann sums for a negative, increasing function will always produce an underestimate for the integral, regardless of squaring the function.
  • Another participant notes that squaring the negative function results in a non-negative function, which could imply that the right-hand Riemann sums may yield an overestimate for positive, increasing functions.
  • There is a subsequent agreement among participants that squaring the function transforms it into a positive, increasing function, leading to the conclusion that right-hand Riemann sums would provide an overestimate.

Areas of Agreement / Disagreement

Participants express disagreement regarding whether the right-hand sums yield an underestimate or an overestimate, with some arguing for underestimation based on the properties of the original function and others asserting overestimation after squaring the function.

Contextual Notes

The discussion does not resolve the implications of the properties of Riemann sums in relation to the transformation of the function through squaring, leaving the mathematical reasoning surrounding the estimates unresolved.

MermaidWonders
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True or False: If $f(x)$ is a negative function that satisfies $f'(x) > 0$ for $0 \le x \le 1$, then the right hand sums always yield an underestimate of $\int_{0}^{1} (f(x))^2\,dx$.

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Would it be true since right hand Riemann sums for a negative, increasing function will always produce an underestimate for the integral, so it doesn't really matter if the entire "function" we're dealing with is squared?
 
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$(f(x))^2\ge0$
 
Or... would it be that squaring $f(x)$ will turn $f(x)$ into a positive function from a negative function, so the statement is going to be false because taking the right Riemann sum will still give you an overestimate for positive, increasing functions?
 
Yeah, OK. So, in that case, it becomes a positive, increasing function, so it's an overestimate, right?
 
That's right.
 

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