Practice Problems

Work through the odd-numbered problems 1-21. Once you have completed the problem set, check your answers.

Answers

1. (a) 2    (b) 0   (c) DNE (does not exist)   (d) 1.5


3. (a) 1    (b) 3    (c) 1    (d) \approx 0.8


5. See Fig. 1.2P5


7. (a) 2     (b) 1   (c) DNE     (d) 2        (e) 2

    (f) 2     (g) 1    (h) 2         (i) DNE


9. (a) When \mathrm{v}=0, \mathrm{~L}=\mathrm{A}.

(b) \lim\limits_{v \rightarrow c^{-}} \mathrm{A} \sqrt{1-\frac{\mathrm{v}^{2}}{\mathrm{c}^{2}}}=0


11. (a) 4    (b) 1    (c) 2    (d) 0    (e) 1    (f) 1


13. (a) Slope of the line tangent to the graph of \mathrm{y}=\cos (\mathrm{x}) at the point (0,1). (b) Slope =0.


15. (a) approx 1    (b) \approx 3.43     (c) \approx 4


17. \begin{array}{ll}\text { at } x=-1: \text { a } & \text { at } x=0: b \quad \text { at } x=1: c \quad d=2: d \\ \text { at } x=3: c \text { at } x=4: b & \text { at } x=5: a\end{array}


19. Verify each step.


21. Several different lists will work. Here is one example.

Put a_{n}=1 /(n \pi) for n=1,2,3, \ldots so a_{n} approaches 0 and \sin \left(a_{n}\right)=\sin \left(\frac{1}{1 /(n \pi)}\right)=\sin (n \pi)=0 for all n.

Put \mathrm{bn} =\frac{1}{2 \mathrm{n} \pi+\pi / 2} for \mathrm{n}=1,2,3, \ldots so \mathrm{bn} approaches 0 and \sin (b n)=\sin (2 n \pi+\pi / 2)=\sin (\pi / 2)=1 for all n.

Put \mathrm{bn} =\frac{1}{2 \mathrm{n} \pi+\pi / 2} for \mathrm{n}=1,2,3, \ldots so \mathrm{bn} approaches 0 and \sin (b n)=\sin (2 n \pi+\pi / 2)=\sin (\pi / 2)=1 for all n.