Question

If k+1,2k+1,k+3 are in ap find the value of k

Answer 1

Question:-

If k + 1, 2k + 1 , k + 3 are in AP , Find the value of k

Solution:-

common difference of an Ap

=> b - a = c - b

=> 2k + 1 - ( k + 1 ) = k + 3 - ( 2k + 1 )

=> 2k + 1 - k - 1 = k + 3 - 2k - 1

=> k = -k + 2

=> 2k = 2

=> k = 1

Method:-2

conditions of an Ap

=> 2b = a + c

=> 2 ( 2k + 1 ) = k + 1 + k + 3

=> 4k + 2 = 2k + 4

=> 2k = 2

=> k = 1

in both cases value of k = 1