Please solve and explain this question in details. 15d16d but i don't know why.

15. The limit 2 2m 11m (1 + ) $4>OO (I; is equal to which of the following? 16. Suppose f is a differentiable function on R whose derivative is given by fl(.'L') : (2x 1)5(L' 3)2(LL' 4). Which of the following statements is true? (a f has a local maximum at J) : 3. (b f has a local minimum at ;L' : 3. (d (e f has no local extrema. ) l (c) f has a local maximum at :1) = 4. ) f has a local minimum at 1 = 4. l