Example 7 - Find equal sets A = {0} B = {x: x > 15 and x < 5}

Example 7 - Chapter 1 Class 11 Sets - Part 2
Example 7 - Chapter 1 Class 11 Sets - Part 3

Go Ad-free

Transcript

Example 7 Find the pairs of equal sets, if any, give reasons: A = {0}, B = {x : x > 15 and x < 5}, C = {x : x – 5 = 0 }, D = {x: x2 = 25}, E = {x : x is an integral positive root of the equation x2 – 2x –15 = 0}. Let’s write all the sets in roster form A = {0} A = {0} B = {x : x > 15 and x < 5}, No number can be greater than 15 and less than 5 simultaneously. B = {} = Φ C = {x : x – 5 = 0} x – 5 = 0 , x = 5 . So, C = {5} D = {x: x2 = 25} x2 = 25 x = ±5 So, D = { +5, −5} E = {x : x is an integral positive root of the equation x2 – 2x –15 = 0}. x2 – 2x −15 =0 x2 – 5x + 3x – 15 =0 x(x – 5) + 3 (x – 5) = 0 (x − 5) (x + 3) = 0 x = 5 , −3 Since x is positive E = {5} Thus, A = {0} B = { } C = {5} D = { +5,-5} E = { 5} Therefore only C = E, as there elements are exactly the same

Davneet Singh's photo - Co-founder, Teachoo

Made by

Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science and Computer Science at Teachoo