Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Relations and Functions

Question:

A relation R from C to R is defined by xRy iff |x| = y. Which of the following is correct?

Options:

(2 + 3i) R 13

3 R (–3)

(1 + i) R 2

iR1

Correct Answer:

iR1

Explanation:

$|2+3 i|=\sqrt{(2)^2+(3)^2}=\sqrt{13} \neq 13$

∴ (2 + 3i) R 13 is wrong.

$|3|=\sqrt{(3)^2+0^2}=\sqrt{9}=3 \neq-3$

∴ 3R (–3) is wrong

$|1+i|=\sqrt{(1)^2+(1)^2}=\sqrt{2} \neq 2$

∴  (1 + i) R2 is wrong

$|1+i|=\sqrt{(1)^2+(1)^2}=\sqrt{2} \neq 2$

∴  iR1 is correct.

Hence (4) is the correct answer.