Continuity and DifferentiabilityHard
Question
The left hand derivative of f(x) = [x] sin (π x) at x = k, k is an integer, is
Options
A.(-1)k (k - 1)π
B.(-1)k-1 (k - 1)π
C.(-1)k kπ
D.(-1)k-1 kπ
Solution
Given f(x) = [x] sin π x
If x is just less than k,[x] = k - 1
∴ f(x) = (k -1) sin π x
LHD of f(x)


where x = k - h
= (-1)k (k - 1)π
If x is just less than k,[x] = k - 1
∴ f(x) = (k -1) sin π x
LHD of f(x)



where x = k - h
= (-1)k (k - 1)π
Create a free account to view solution
View Solution FreeMore Continuity and Differentiability Questions
Given f(x) = b ([x]2 + [x]) + 1 for x ≥ -1 = sin (π(x + a)) for x < -1where [x] denotes the integral part ...The derivative of cot−1 at x = π/6 is-...Differential coefficient of with respect to sin−1 x is -...If f is a real-valued differentiable function satisfying | f(x) - f(y) | ≤ (x - y)2, x, y ∈ R and f(0) = 0, ...d/dx (ax) equals-...