which appears to be different.
(b) Let h = 0.001. The graph of
in 
appears to be a sinusoid. It is a sinusoid because
is the sum of three sinusoids all with period 
Section 5.2, Extension of Exercise 69 (page 438) Answers
(a) They are not equal but are very close. It is difficult to find a viewing window in
which appears to be different.
(b) Let h = 0.001. The graph of in appears to be a
sinusoid. It is a sinusoid because is the sum of three sinusoids all with period
Art instructions: The scale marks are 
on the horizontal axis and are 0.01 on the
vertical axis.
(c) The graph of in the window shows that the error in the approximation 
is less than 0.001 because 
Section 5.3, Extension of Exercise 63 (page 445)
Answers
Section 5.4
Extension of Exercise 57 (page 452)
Answers
Let x = 1 stand for January, s = 2 for February, and so forth. The modified table is
| Month | High Temp | Low Temp |
| 1 | 78 | 64.5 |
| 2 | 78.5 | 62.5 |
| 3 | 78.5 | 62.5 |
| 4 | 81.5 | 65 |
| 5 | 85 | 68 |
| 6 | 87 | 69.5 |
| 7 | 89.5 | 76 |
| 8 | 92.5 | 77 |
| 9 | 92.5 | 78 |
| 10 | 88 | 76.5 |
| 11 | 85 | 67.5 |
| 12 | 81.5 | 67.5 |
(a) The regression equation is approximately 
The fit is good. Art instructions: The scale marks are 1 on the horizontal axis and 10 on the vertical axis.
(b) The regression equation is approximately 
The fit is good. Art instruction: The scale marks are 1 on the horizontal axis and 10 on the vertical axis.
(c) Temperatures should be reasonably periodic.