Find the exact value of 57x2dx\displaystyle {\int_{{5}}^{{7}}}{x}^{{2}}{\left.{d}{x}\right.}  .  Find the error of approximation between the exact value and the value calculated using the trapezoidal rule with four subdivisions.  Draw a graph to illustrate.

The exact value is:   

The error in the approximation is:

Give your answer accurate to four decimal places.