Let K be the set of all real values of x where the function f(x) = sin |x| -- |x| + 2(x -- \[\pi \]) cos |x| is not differentiable. Then the set K is equal to :
Solutions · 1
Official solution
f(x) = sin\[\left| x \right| - \left| x \right|\] + 2(x - \[\pi \]) cosx
\[ \because \] sin\[\left| x \right|\] - \[\left| x \right|\] is differentiable function at c = 0
\[ \therefore \] k = \[\phi \]