The area A of the region S that lies under the graph of the continuous function is the limit of the sum of the areas of approximating rectangles.

A =limn R_n=limn [f(x₁)x + f(x₂)x + . . . + f(x_n)x]

Use this definition to find an expression for the area under the graph of f as a limit. Do not evaluate the limit.

f(x) =

ln(x) /x

, 4 x 13