Given : f(x)=[x]+|sinx| and x∈(0,10)
We know, [x] is not differentiable when x∈Z
⇒ It is not differentiable at 9 integral points.
and |sinx| is not differentiable when x∈nπ, where n is an integer.
⇒|sinx| is not differentiable at x=π,2π,3π
Hence, f(x) is not differentiable at 12 points.