Amethod for determining whether a critical point is a minimum, maximum, or neither using the slope of the curvea) first derivative testb) absolute maximumc) accelerationd) concavity

a. First derivative

Step-by-step explanation:

To determine the nature of the stationary points:

Either  Find  dy/dx or d2y/dx2

If the result is: positive—the point is a minimum one; negative—the point is a maximum one; zero—the point is a point of inflexion

or

Determine the sign of the gradient of the curve just before and just after the stationary points.

If the sign change for the gradient of the curve is: positive to negative—the point is a maximum one; negative to positive—the point is a minimum one; positive to positive or negative to negative— the point is a point of inflexion