The left-hand derivative of f(x) = [x] sin(πx) at x = k, k is an integer is
(a) (–1) k (k – 1)π (b) (–1) k – 1 (k – 1)π (c) (–1) k kπ (d) (–1) k – 1 kπ
hey bro @nev cant we write pi(k-1)(-1)^(k-1)Sinhpi/(-1) as -pi(k-1)(-1)^(k-1)Sinhpi/1 and then (-1)pi(k-1)(-1)^(k-1)Sinhpi then pi(k-1)(-1)^(k-1+1)Sinhpi so giving pi(k-1)(-1)^(k)Sinhpi.. hope this helps u bro...:)