JEE Main 2019 Mathematics question
If m is the minimum value of k for which the function is increasing in the interval [0, 3] and M is the maximum value of f in [0, 3] when k = m, then the ordered pair (m, M) is equal to:
Answer: (B)
Solution
f′ ∝ 3kx − 4x ≥ 0 on [0, 3] ⇒ k ≥ 4; M = f(3) = 3√3.