Solutions

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+52x22x+10f(x)=12x3+52x22x+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. 52,6,652,6,6

23. 2,4,322,4,32

25. 4, –4, –5

27. 5,3,125,3,12

29. 12,1+52,15212,1+52,152

31. 3232

33. 2, 3, –1, –2

35. 12,12,2,312,12,2,3

37. 1,1,5,51,1,5,5

39. 34,1234,12

41. 2,3+2i,32i2,3+2i,32i

43. 23,1+2i,12i23,1+2i,12i

45. 12,1+4i,14i12,1+4i,14i

47. 1 positive, 1 negative
Graph of f(x)=x^4-x^2-1.

49. 3 or 1 positive, 0 negative
Graph of f(x)=x^3-2x^2+x-1.

51. 0 positive, 3 or 1 negative
Graph of f(x)=2x^3+37x^2+200x+300.

53. 2 or 0 positive, 2 or 0 negative
Graph of f(x)=2x^4-5x^3-5x^2+5x+3.

55. 2 or 0 positive, 2 or 0 negative
Graph of f(x)=10x^4-21x^2+11.

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+x2x1)f(x)=49(x3+x2x1)

69. f(x)=15(4x3x)f(x)=15(4x3x)

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