1.

Find the value of n so that `(a^(n+1)+b^(n+1))/(a^n+b^n)`may be the geometric mean between a and b.

Answer» As given expession is geometric mean of `a` and `b`.
`(a^(n+1)+b^(n+1))/(a^n+b^n) = (ab)^(1/2)`
`=>(a^(n+1)+b^(n+1)) = a^(n+1/2)b^(1/2)+b^(n+1/2)a^(1/2)`
`=>a^(n+1)-a^(n+1/2)b^(1/2) = b^(n+1/2)a^(1/2)-b^(n+1)`
`=>a^(n+1/2)(a^(1/2)-b^(1/2)) = b^(n+1/2)(a^(1/2)-b^(1/2))`
`=>(a/b)^(n+1/2) = 1`
As `a !=b`,
`:. n+1/2 = 0`
`n = -1/2`


Discussion

No Comment Found

Related InterviewSolutions