Question
Test whether the following relations $R_1$ are:
  1. Reflexive.
  2. Symmetric.
  3. Transitive.
$R_1$ on $Q_0$ defined by $(\text{a, b})\in\text{R}_1\Leftrightarrow\ \text{a}=\frac{1}{\text{b}}.$

Answer

$\text{R}_1=\Big\{(\text{x, y}),\ \text{x, y}\in\text{Q}_0, \text{x}=\frac{1}{\text{y}}\Big\}$
Reflexivity: Let, $\text{x}\in\text{Q}_0$
$\Rightarrow\ \text{x}\neq\frac{1}{\text{x}}$
$\Rightarrow\ (\text{x, x})\in\text{R}_1$
$\therefore R_1$ is not reflexive.
Symmetric: Let, $(\text{x, y})\in\text{R}_1$
$\Rightarrow\ \text{x}=\frac{1}{\text{y}}$
$\Rightarrow\ \text{y}=\frac{1}{\text{x}}$
$\Rightarrow\ (\text{y, x})\in\text{R}_1$
$\therefore R_1$ is Symmetric.
Transitive: Let, $(\text{x, y})\in\text{R}_1$ and $(\text{y, z})\in\text{R}_1$
$\Rightarrow\ \text{x}=\frac{1}{\text{y}}$ and $\text{y}=\frac{1}{\text{z}}$
$\Rightarrow\ \text{x}=\text{z}$
$\Rightarrow\ (\text{x, z})\notin\text{R}_1$
$\therefore R_1$ is not Transitive.

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Evaluate the following integrals:$\int\limits^4_1\big\{|\text{x}-1|+|\text{x}-2|+|\text{x}-4\big\}\text{dx}$
Evaluate the following integrals as limit of sum:$\int\limits^5_{3}(2-\text{x})\text{dx}$
Assume that each born child is equally likely to be a boy or a girl. If a family has two children, then what is the constitutional probability that both are girls? Given that.
  1. The youngest is a girl,
  2. At least one is a girl.
Sketch the graph y = |x + 1|. Evaluate $\int\limits_{-4}^{2}|\text{x}+1|\text{dx} $ . What does this value of the integral represent on the graph.
If $\text{x}=\sin\Big(\frac{1}{\text{a}}\log\text{y}\Big),$ show that $(1-\text{x}^2)\text{y}_2-\text{xy}_1-\text{a}^2\text{y}=0$
A firm manufacturing two types of electric items, A and B, can make a profit of Rs. 20 per unit of A and Rs. 30 per unit of B. Each unit of A requires 3 motors and 4 transformers and each unit of B requires 2 motors and 4 transformers. The total supply of these per month is restricted to 210 motors and 300 transformers. Type B is an export model requiring a voltage stabilizer which has a supply restricted to 65 units per month. Formulate the linear programing problem for maximum profit and solve it graphically.
Find the shortest distance between the following pairs of lines whose vector equation are:
$\vec{\text{r}}=\big(2\hat{\text{i}}-\hat{\text{j}}-\hat{\text{k}}\big)+\lambda\big(2\hat{\text{i}}-5\hat{\text{j}}+2\hat{\text{k}}\big)$ and, $\vec{\text{r}}=\big(\hat{\text{i}}+2\hat{\text{j}}+\hat{\text{k}}\big)+\mu\big(\hat{\text{i}}-\hat{\text{j}}+\hat{\text{k}}\big)$
Evalute the following integrals:
$\int\frac{\sin(\text{x}-\text{a})}{\sin(\text{x}-\text{b})}\text{dx}$
The odds against a certain event are 5 to 2 and the odds in favour of another event, independent to the former are 6 to 5. Find the probability that,
  1. At least one of the events will occur,
  2. None of the events will occur.
The probability that a certain person will buy a shirt is 0.2, the probability that he will buy a trouser is 0.3, and the probability that he will buy a shirt given that he buys a trouser is 0.4. Find the probability that he will buy both a shirt and a trouser. Find also the probability that he will buy a trouser given that he buys a shirt.