1.

If `f(x) = 3x + 6 ,g(x) = 4x + k` and `fog(x) = gof(x) ` then k …..A. `-9`B. 18C. `(1)/(9)`D. 9

Answer» Correct Answer - D
We have,
`f(x) = 3x + 6, g(x) = 4x + k`
Since, for (X) = gof (x)
`implies f(g) (x) = g(f(x))`
`implies f(4x + k) = g(3x + 6)`
`implies 3(4x + k) + 6 = 4 (3x + 6) + k`
`implies 3k - k = 24 - 6`
`implies 2k = 18`
`implies k = 9`


Discussion

No Comment Found

Related InterviewSolutions