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Ex 9.2
Ex 9.2, 2 Deleted for CBSE Board 2023 Exams
Ex 9.2, 3 Important Deleted for CBSE Board 2023 Exams
Ex 9.2, 4 Deleted for CBSE Board 2023 Exams
Ex 9.2, 5 Important Deleted for CBSE Board 2023 Exams
Ex 9.2, 6 Deleted for CBSE Board 2023 Exams
Ex 9.2, 7 Important Deleted for CBSE Board 2023 Exams
Ex 9.2, 8 Deleted for CBSE Board 2023 Exams
Ex 9.2, 9 Important Deleted for CBSE Board 2023 Exams
Ex 9.2, 10 Deleted for CBSE Board 2023 Exams
Ex 9.2, 11 Important Deleted for CBSE Board 2023 Exams
Ex 9.2, 12 Deleted for CBSE Board 2023 Exams
Ex 9.2, 13 Deleted for CBSE Board 2023 Exams
Ex 9.2, 14 Important
Ex 9.2, 15 Important
Ex 9.2, 16 Important Deleted for CBSE Board 2023 Exams
Ex 9.2, 17 Deleted for CBSE Board 2023 Exams
Ex 9.2, 18 Important Deleted for CBSE Board 2023 Exams
Ex 9.2
Last updated at March 22, 2023 by Teachoo
Ex 9.2 , 1 Find the sum of odd integers from 1 to 2001. Integers from 1 to 2001 are 1, 2, 3, 4, .2001 Odd integers from 1 to 2001 are 1,3,5, 1999,2001 This sequence forms an A.P as difference between the consecutive terms is constant. So, the A.P. is 1,3,5, 1999,2001 Here First term = a = 1 Common difference = d = 3 1 = 2 & last term = l = 2001 First, we will find number of terms, i.e. n We know that an = a + (n 1)d where an = nth term , n = number of terms, a = first term , d = common difference Here, an = last term = l = 2001 , a = 1 , d = 2 2001 = 1 + (n 1)2 2001 = 1 + 2n 2 2001 1 = 2n 2 2001 1 + 2 = 2n 2002 = 2n 2002/2 = n 1001 = n n = 1001 To calculate sum of odd integers, we use the formula Sn = n/2 [a + l] Here, n = 1001 , l = 2001 & a = 1 Sn = 1001/2 [1 + 2001] = 1001/2 2002 = 1001 1001 = 1002001 Hence the sum of odd integers from 1 to 2001 is 1002001