The table below shows partial values of the function f (x). Use a trapezoid sum with 4 sub-intervals to estimate the area between the graph of f and the x-axis on [0,1].
Each sub-interval has width 0.25. First trapezoid, on [0,0.25]:
Second trapezoid, on [.25,.5]:
Third trapezoid, on [.5,.75]:
Fourth trapezoid, on [0.75,1]:
We add the areas of the trapezoids and get
0.75 + 1.25 + 1.875 + 2.5 = 6.375.