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Example 10 - Show that  5 - root 3 is irrational - Chapter 1 - Examples

Example 10 - Chapter 1 Class 10 Real Numbers - Part 2
Example 10 - Chapter 1 Class 10 Real Numbers - Part 3

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Example 6 Show that 5 - 3 is irrational. We have to prove 5 - 3 is irrational Let us assume the opposite, i.e., 5 - 3 is rational Hence, 5 - 3 can be written in the form / where a and b (b 0) are co-prime (no common factor other than 1) Hence, 5 - 3 = / 3 = / - 5 3 = ( 5 )/ 3 = ( 5 )/ 3 = (( 5 )/ ) 3 = (5 )/ Here, ( +5 )/ is a rational number But 3 is irrational Since, Rational Irrational This is a contradiction Our assumption is incorrect Hence, 5 - 3 is irrational Hence proved.

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Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 13 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.