[填空题]
A function is given /9-a; i iaiukhu2s3w)qg3:5l pq c nama 6 m7/,0napw;j gc r.uni-nezby $f(x)=4 x^{3}-x for -\frac{1}{2} \leq x \leq \frac{1}{2}$ .
1. Sketch the graph of f for the given domain, labelling all intercepts and stationary points.
2. Find an approximation for $I=$\int_{0}^{1 / 2} f(x) \mathrm{d} x$$ using the trapezoidal rule with a strip width of 0.1 .
3. Find the exact value of I in part (b).The exact value of I is -
4. Explain why the approximation found in part (b) is larger than the exact value found in part (c).
5. Write down the value of $J=\int_{-1 / 2}^{1 / 2} f(x) \mathrm{d} x$ without calculation. Give a reason for your answer.
I= .
