If three equal subdivisions of [-4, 2] are used, find the trapezoidal approximation of integral of (e^(-x))/2 dx from -4 to 2.

answer: evaluate the objective function at each vertex to determine which - and -values, if any, maximize or minimize the function. example: find the minimum value and maximum value of the objective function f ( x , y ) = 4 x + 5 y , subject to the following constraints