[填空题]
The following diagram shows a section of a curve y=f( k-1s fqsn/or,1 el.chx) and the coordinates o/aiq -c:/xml)aob c0dpnt9 w(f six pbt qi-mlc)x(anp/aoc0 d/ w9: oints that lie on the curve.
1. Estimate the area of the shaded region, giving your answer to two decimal places.
$\int_{1}^{5} y \mathrm{~d} x$ $\approx$ units^2
The equation of the curve was found to be y=2 $x^{2}-4 x+20$ .
2. Write an integral that represents the area of the shaded region.
A= $\int_{1}^{5}\left(a x^{2}-b x+c\right) \mathrm{d} x$; a= ,b= ,c= .
3 . Find the area of the shaded region, giving your answer in exact values.
A=$\frac{a}{b}$ $units^2$ ; a= ,b= .
4. Find the percentage error between the estimation in part (a) and the exact value found in part (c).
