Solutions to Try Its
1. f(−3)=−412f(−3)=−412
2. The zeros are 2, –2, and –4.
3. There are no rational zeros.
4. The zeros are -4, 12, and 1.-4, 12, and 1.
5. f(x)=−12x3+52x2−2x+10f(x)=−12x3+52x2−2x+10
6. There must be 4, 2, or 0 positive real roots and 0 negative real roots. The graph shows that there are 2 positive real zeros and 0 negative real zeros.
7. 3 meters by 4 meters by 7 meters
Solutions to Odd-Numbered Exercises
1. The theorem can be used to evaluate a polynomial.
3. Rational zeros can be expressed as fractions whereas real zeros include irrational numbers.
5. Polynomial functions can have repeated zeros, so the fact that number is a zero doesn’t preclude it being a zero again.
7. –106
9. 0
11. 255
13. –1
15. –2, 1, 1212
17. –2
19. –3
21. −52,√6,−√6−52,√6,−√6
23. 2,−4,−322,−4,−32
25. 4, –4, –5
27. 5,−3,−125,−3,−12
29. 12,1+√52,1−√5212,1+√52,1−√52
31. 3232
33. 2, 3, –1, –2
35. 12,−12,2,−312,−12,2,−3
37. −1,−1,√5,−√5−1,−1,√5,−√5
39. −34,−12−34,−12
41. 2,3+2i,3−2i2,3+2i,3−2i
43. −23,1+2i,1−2i−23,1+2i,1−2i
45. −12,1+4i,1−4i−12,1+4i,1−4i
47. 1 positive, 1 negative
49. 3 or 1 positive, 0 negative
51. 0 positive, 3 or 1 negative
53. 2 or 0 positive, 2 or 0 negative
55. 2 or 0 positive, 2 or 0 negative
57. ±5,±1,±52±5,±1,±52
59. ±1,±12,±13,±16±1,±12,±13,±16
61. 1,12,−131,12,−13
63. 2,14,−322,14,−32
65. 5454
67. f(x)=49(x3+x2−x−1)f(x)=49(x3+x2−x−1)
69. f(x)=−15(4x3−x)f(x)=−15(4x3−x)
71. 8 by 4 by 6 inches
73. 5.5 by 4.5 by 3.5 inches
75. 8 by 5 by 3 inches
77. Radius = 6 meters, Height = 2 meters
79. Radius = 2.5 meters, Height = 4.5 meters
Candela Citations
- Precalculus. Authored by: Jay Abramson, et al.. Provided by: OpenStax. Located at: http://cnx.org/contents/fd53eae1-fa23-47c7-bb1b-972349835c3c@5.175. License: CC BY: Attribution. License Terms: Download For Free at : http://cnx.org/contents/fd53eae1-fa23-47c7-bb1b-972349835c3c@5.175.