Let f (x)= |cosx|. Then :1f is everywhere differentiable.2f is everywhere continuous but not differentiable at n = nπ, n∈Z.3f is everywhere continuous but not differentiable at x = (2n + 1) π/2, n∈ Z .4None of these.Answer & explanation+Correct answer: option 3Try to differentiate |cos x|, you'll see it is not-differential.
