Final answer:
The true statements are A) If f′(x)=0, x is a critical point and B) The derivative of a constant function is always zero.
Step-by-step explanation:
The true statements are A) If f′(x)=0, x is a critical point and B) The derivative of a constant function is always zero.
Statement A is true because if the derivative f'(x) is equal to zero at a point x, then x is a critical point of the function. This means that the function may have a local maximum, local minimum, or a point of inflection at x.
Statement B is true because the derivative of a constant function is always zero. This is because a constant function does not change as x varies, so its rate of change (the derivative) is zero.