[填空题]
The following diagram shows a sectio ; rn4 /rcf-pcynmc10ypwz)0tn of a curve y=f(x) and t79(b(lcm d* o bwwdqt9he coordinates of six points thatdc7 boq9(l 9wtwm *bd( 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).
