Question

If k,2k-1 and 2k+1 are three consecutive terms of an AP, then the value of k is

Answer 1

EXPLANATION.

• GIVEN

K, 2K - 1, 2K + 1 are the three consecutive terms of an Ap

TO FIND VALUE OF K.

METHOD = 1.

Let a, b, c are in ap

Therefore,

b - a = c - b

2k - 1 - (k) = 2k + 1 - ( 2k - 1)

2k - 1 - k = 2k + 1 - 2k + 1

k - 1 = 2

k = 3

METHOD = 2.

conditions of an Ap =

2b = a + c

put the value in this conditions

we get,

2(2k - 1 ) = k + 2k + 1

4k - 2 = 3k + 1

k = 3

Therefore,

value of k = 3