QJEEM20Mada96: JEE Main 2020 Mathematics - Class 12 JEEM20Mada96 Solution: Let S be the set of points where the function, ƒ(x) =…

f(x) is non-differentiable at x = 1, 3, 5

$$\therefore$$ S is {1, 3, 5}

$$\sum _{x\in S}f(f(x))$$

= f(f(1)) + f(f(3)) + f(f (5))

= f(0) + f(2) + f(0)

= 1 + 1 + 1 = 3