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Example 12 - Check whether 7 root 5, ... are irrational - Examples

Example 12 - Chapter 1 Class 9 Number Systems - Part 2
Example 12 - Chapter 1 Class 9 Number Systems - Part 3

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Example 12 - Chapter 1 Class 9 Number Systems - Part 4 Example 12 - Chapter 1 Class 9 Number Systems - Part 5

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Example 12(Method 1) Check whether 7 5, 7/ 5, 2 + 21, 2 are irrational numbers or not. 7 7 is rational 5 = 2.236 . which is non- terminating non-repeating is an irrational number We know that Rational Irrational = Irrational Since, 7 5 = 7 5 it is irrational / 7 is rational 5 = 2.236 . which is non- terminating non-repeating is an irrational number We know that / = Irrational Thus, 7/ 5 is irrational + 21 21 is rational 2 " = 1.4142 " which is non- terminating non-repeating is an irrational number We know that Irrational + Rational = Irrational Thus, 2 + 21 is an irrational number 2 2 is rational = 3.1415 . which is non- terminating non-repeating is an irrational number We know that Irrational Rational = Irrational Thus, - 2 is an irrational number Example 12 (Method 2) Check whether 7 5, 7/ 5, 2 + 21, 2 are irrational numbers or not. 7 5 = 2.236 . 7 5 = 7 (2.346) = 15.652 .., It is a non-terminating and non-repeating decimal expansion. So,7 5 is an irrational number / 7/ 5 = (7 5)/( 5 5) = (7 5)/5 = 7/5 (2.346) = 3.1304 . It is a non-terminating and non-repeating decimal expansion. So, 7/ 5 is an irrational number + 21 2 = 1.4142 2 + 21 = 1.4142 + 21 = 22.4142 , It is a non-terminating and non-repeating decimal expansion. So, 2 + 21 is an irrational number 2 = 3.1415 . 2 = 3.1415 . 2 = 1.1415 It is a non-terminating and non-repeating decimal expansion. So, - 2 is an irrational number

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Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 12 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.