760.
The function is not suitable to apply Rolle's theorem, since
f(x) is not continuous on [1, 5]
f(1) f(5)
f(x) is continuous only at x = 4
f(x) is not differentiable at x = 4
D.
f(x) is not differentiable at x = 4
Given,
Differentiability at x = 4,
Hence, f(x) is not differentiable at x = 4.