Answer:
Explanation:
Differentiability at a point implies no sudden changes in the slopes from one side to the other; that is, the derivative must have the same value.
Differentiating x^2 - 6 and 6 - x^2, we get 2x = -2x, whose only solution is zero (0). The two halves of the given function have the same slope (0) at x = 0.