For a linear function, the instantaneous rate of change is everywhere equal to the slope. Thus the rate of change of the function h(x)=2x on the interval 2≤x≤4 The rate of change of the function given will equal to its slope, thus; slope,m=(y-1-y)/(x_1-x) =(2*4-2*2)/(4-2) =(8-4)/2 =4/2 =2
