Let \(f(x)=x,\ 0\le x\le 1\) and \(p=0,\frac{1}{4},\frac{1}{2},\frac{3}{4},1\) be the partition of [0, 1]. Find U(p, f) and L(p, f).


A) \(\Large \frac{1}{8},\frac{1}{8}\)

B) \(\Large \frac{3}{8},\frac{7}{8}\)

C) \(\Large \frac{5}{8},\frac{3}{8}\)

D) \(\Large \frac{7}{8},\frac{9}{8}\)

Correct Answer:
C) \(\Large \frac{5}{8},\frac{3}{8}\)

Description for Correct answer:
\(\Large P=\{0,\frac{1}{4},\frac{1}{2}\frac{3}{4},1\}\)

sub intervals are

\(\Large \left[ 0,\frac{1}{4} \right],\left[ \frac{1}{4},\frac{1}{2} \right],\left[ \frac{1}{2},\frac{3}{4} \right],\left[ \frac{3}{4},1 \right]\)

since \(f(x)=x\)

\(\Large \Rightarrow m_{1}=0;\ m_{2}=\frac{1}{4},\ m_{3}=\frac{1}{2},\ m_{4}=\frac{3}{4}\)

\(\Large \Rightarrow M_{1}=\frac{1}{4};\ M_{2}=\frac{1}{2};\ M_{3}=\frac{3}{4};\ M_{4}=1\)

\(\Delta x_{1}=\Delta x_{2}=\Delta x_{3}=\Delta x_{4}=\Large\frac{1}{4}\)

\(U(P,f)=\sum\limits_{r=1}^{4}m_{r}\Delta x_{r}\)

\(\Large =\frac{1}{4}.\frac{1}{4}+\frac{1}{2}.\frac{1}{4}+\frac{3}{4}.\frac{1}{4}+1.\frac{1}{4}\)

\(=\frac{5}{8}\)

\(L(P,f)=\sum\limits_{r=1}^{4}m_{r}\Delta x_{r}\)

\(\Large =0.\frac{1}{4}+\frac{1}{4}.\frac{1}{4}+\frac{1}{2}.\frac{1}{4}+\frac{3}{4}.\frac{1}{4}\)

\(\Large =0+\frac{1}{16}+\frac{1}{8}+\frac{3}{16}\)

\(\Large =\frac{3}{8}\)

Part of solved Real Analysis questions and answers : >> Elementary Mathematics >> Real Analysis








Comments

No comments available




Similar Questions
1). Let f(x) be defined on [0, 1] as follows:\[ f(x) = 1\begin{cases}\text{1 when } x \text{ is rational}\\\text{-1 when } x\text{ is irrational}\end{cases}\]
A). Riemann integrable
B). not Rimann integrable
C). continuous
D). none of these
-- View Answer
2). Let \(f(x)=\frac{1}{x}\ 0\le x\le 2\ P=\{ 1,1.2,1.4,1.6,1.8,2 \}\) Find \(w(P,f)\)
A). 0,1
B). 0.2
C). 0.3
D). none of these
-- View Answer
3). \(f(x)=x^{2}\). Find \(\int\limits_{\overline{0}}^{a}\) and \(\int\limits_{n}^{\overline{0}}f\)
A). \(\Large \frac{a}{3},\frac{a}{3}\)
B). \(\Large \frac{a^{2}}{3},\frac{a^{2}}{3}\)
C). \(\Large \frac{a^{3}}{3},\frac{a^{3}}{3}\)
D). none of these
-- View Answer
4). Any countable infinite Set is equivalent to a
A). subset
B). proper subset
C). null set
D). none of these
-- View Answer
5). \(Q \times Q\) is
A). uncountable
B). countable
C). finitgset
D). infinite set
-- View Answer


6). (0, 1] is
A). countable
B). uncountable
C). finite
D). none of these
-- View Answer
7). The set of irrational numbers lying in the interval (0, 1] is
A). countable
B). finite
C). uncountable
D). none of these
-- View Answer
8). The set \(P_{n}\) of all polynomials with integer coefficients is
A). countable
B). uncountable
C). finite
D). none of these
-- View Answer
9). R is equivalent
A). (0, 1)
B). (0, 1]
C). [0, 1]
D). none of these
-- View Answer
10). Which of the following is not true?
A). Cantor set is measurable and its measure zero
B). Cantor set is equivalent to [0, 1]
C). Cantor set is uncountable
D). Cantor set is countable
-- View Answer