Use the table of values to estimate

Question

⌠6
⎮ f(x)⋅dx
⌡0

Use three sub intervals and the (a) left endpoints, (b) right endpoints, and (c) midpoints. If f is an increasing function, how does each estimate compare with the actual value? Explain your reasoning.

x:
{ 0, 1, 2, 3, 4, 5, 6}

f(x):
{-6, 0, 8,18,30,50,80}