Question

Which of the following functions is differentiable at x = 0 ?

• A. cos (|x|) + |x|
• B. cos (| x |) - |x |
• C. sin (|x|) + |x|
• D. sin (|x|) - |x|.

Answer 1

Answer: (D)

Correct answer is (d) sin (|x|) - |x|.