[填空题]
Consider the region enclosed by the graph of th2fe2m8w juow ,e function f(x)=z p:l +ys daio.+20llj1-hnr ncnl- c)$e^{x / 2}$ , the x -axis and the vertical lines x=0 and x=3 .
1. Sketch the function f and shade in the region.
2. 1. Write down a definite integral that represents the shaded region, it is $\text { 1. } \int_{a}^{3} e^{x / b} \mathrm{~d} x \backslash$,a= ,b= .
2. Calculate the area of the shaded region is .
3. Use the trapezoidal rule with n=6 trapeziums to estimate the area of the region.
