- Home
- Standard 11
- Mathematics
1.Set Theory
medium
Let $A, B,$ and $C$ be the sets such that $A \cup B=A \cup C$ and $A \cap B=A \cap C$. Show that $B = C$
Option A
Option B
Option C
Option D
Solution
Let, $A, B$ and $C$ be the sets such that $A \cup B=A \cup C$ and $A \cap B=A \cap C$.
To show: $B = C$
Let $x \in B$
$\Rightarrow x \in A \cup B \quad[B \subset A \cup B]$
$\Rightarrow x \in A \cup C \quad[A \cup B=A \cup C]$
$\Rightarrow x \in A$ or $x \in C$
Case $I$
Also, $x \in B$
$\therefore x \in A \cap B$
$\Rightarrow x \in A \cap C \quad[\because A \cap B=A \cap C]$
$\therefore x \in A$ and $x \in C$
$\therefore x \in C$
$\therefore B \subset C$
Similarly, we can show that $C \subset B$
$\therefore B=C$
Standard 11
Mathematics
Similar Questions
Match each of the set on the left in the roster form with the same set on the right described in set-builder form:
| $(i)$ $\{1,2,3,6\}$ | $(a)$ $\{ x:x$ is a prime number and a divisor $6\} $ |
| $(ii)$ $\{2,3\}$ | $(b)$ $\{ x:x$ is an odd natural number less than $10\} $ |
| $(iii)$ $\{ M , A , T , H , E , I , C , S \}$ | $(c)$ $\{ x:x$ is natural number and divisor of $6\} $ |
| $(iv)$ $\{1,3,5,7,9\}$ | $(d)$ $\{ x:x$ a letter of the work $\mathrm{MATHEMATICS}\} $ |
medium
