Q2 of 167 Page 19

Insert 4 A.M.s between 4 and 19.

Let A1, A2, A3, A4 be the 4 AM Between 4 And 19


Then, 4, A1, A2, A3, A4, 19 are in AP


We know,


An = a + (n - 1)d


a6 = 19 = 4 + (6 - 1)d


d = 3


Hence,


A1 = a + d = 4 + 3 = 7


A2 = A1 + d = 7 + 3 = 10


A3 = A2 + d = 10 + 3 = 13


A4 = A3 + d = 13 + 3 = 16


More from this chapter

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7

Show that x2 + xy + y2, z2 + zx + x2 and y2 + yz + z2 are in consecutive terms of an A.P., if x, y and z are in A.P.

 1

Find the A.M. between:

(i) 7 and 13 (ii) 12 and - 8 (iii) (x - y) and (x + y)

 3

Insert 7 A.M.s between 2 and 17.

 4

Insert six A.M.s between 15 and - 13.