Practicing Success
The relation R defined in A = {1, 2, 3} by aRb if |a2 − b2| ≤ 5. Which of the following is false? |
R = {(1, 1) (2, 2), (3, 3), (2, 1), (1, 2), (2, 3), (3, 2)} R–1 = R Domain of R = (1, 2, 3) Range of R = {5} |
Range of R = {5} |
Let a = 1 ∴ $\left|a^2-b^2\right| \leq 5 ⇒\left|1-b^2\right| \leq 5$ $⇒\left|b^2-1\right| \leq 5 ⇒ b = 1, 2$ Let ⇒ a = 2 ∴ $\left|a^2-b^2\right| \leq 5$ ⇒ $\left|b^2-4\right| \leq 5$ ⇒ b = 1, 2, 3 Let $⇒ a=3 ∴\left|a^2-b^2\right| \leq 5 ⇒\left|9-b^2\right| \leq 5$ $⇒ a=3 ∴\left|a^2-b^2\right| \leq 5 ⇒\left|9-b^2\right| \leq 5$ ∴ R = {(1, 1), (1, 2), (2, 1), (2, 2), (2, 3), (3, 3)} = R Domain of R = {x : (x, y) ∈ R} = {1, 2, 3}. Range of R = {y : (x, y) ∈ R} = {1, 2, 3}. Hence (4) is the correct answer. |