InterviewSolution
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InterviewSolution
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Using identity, find the value of(i) (4.9)2(ii) (100.1)2(iii) (1.9) x (2.1) |
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Answer» (i) (4.9)2 (4.9)2 = (5 – 0.1)2 Substituting a = 5 and b = 0.1 in (a – b)2 = a2 – 2ab + b2, we have (5 – 0.1)2 = 52 – 2(5) (0.1) + (0.1)2 (4.9)2 = 25 – 1 + 0.01 = 24 + 0.01 (4.9)2 = 24.01 (ii) (100.1)2 (100.1)2 = (100 + 0.1)2 Substituting a = 100 and b = 0.1 in (a + b)2 = a2 + 2ab + b2, we have (100 + 0.1)2 = (100)2 + 2(100) (0.1) + (0.1)2 (100.1)2 = 10000 + 20 + 0.01 (100.1)2 = 10020.01 (iii) (1.9) x (2.1) (1.9) x (2.1) = (2 – 0.1) x (2 + 0.1) Substituting a = 100 and b = 0.1 in (a – b) (a + b) = a2 – b2 we have (2 – 0.1) (2 + 0.1) = 22 – (0.1)2 (1.9) x (2.1) = 4 – 0.01 (1.9) (2.1) = 3.99 |
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