Section outline

  • Section 3.2: Quadratic Functions
    ::第3.2节:赤道功能

    1. The graph of a quadratic is called a  parabola.
      ::二次曲线的图叫做抛物线。
    2. A parabola opens up if the leading coefficient is positive.
      ::如果主要系数为正数,则开启抛物线。
    3. If the coefficient of y  is positive, the parabola opens right.
      ::如果y的系数是正数,则抛物线打开正确。
    4. The vertex is the extreme (lowest or highest) point of a parabola that opens up or down.
      ::顶点是向上或向下打开的抛物线的极端(最低或最高)点。
    5. The line of symmetry divides a parabola in two symmetrical parts.
      ::对称线将抛物线分为两个对称部分。
    6. The graph is a parabola with the vertex at (0, 3).

      ::该图是一个抛物线,顶点为(0, 3) 。
    7. The parabola opens down, with the vertex at (2, 0).

      ::抛物线向下打开,顶部为(2,0)。
    8. The parabola opens up, is narrower than the reference, and has a vertex at (-2, -8).

      ::抛物线打开,比引用范围小,在( 2 - 8) 有顶点( 2 - 8) 。
    9. a. The parabola opens down.
      b. The vertex is at (-1, 2)
      c. It is not stretched, but reflected across the x -axis and shifted left 1 and up 2.
      ::a. 抛物线向下打开。b. 顶部为(-1, 2), c. 不伸展,但反射到X轴,左转1, 上移2。
    10. y = 6 x 2  is the narrowest because it is stretched vertically the most.
      ::y=6x2 是最窄的,因为它垂直伸展最多。
    11. y = - x 2  

      ::y=-x2 y=-x2
    12. y = 3 x 2 + 6 x + 1  

      ::y=3x2+6x+1
    13. y = 1 2 x 2 + 2 x + 4  

      ::y=12x2+2x+4
    14. y = ( x 3 ) 2 + 4  

      ::y=(x-3)2+4
    15. y = - x 2 8 x 17  

      ::y=-x2-8x-17
    16. Maximum height is 11.25 yds.
      ::最大高度为11.25 yds。
    17. At max height, the ball is 15 yds down the field.
      ::在最高高度,球在球场下方15岁

    18. You could determine the height and distance by approximating the vertex (the highest point), knowing that the line of symmetry is halfway between 0 and 30. Thus, the vertex is about (15, 11).
      ::了解对称线介于0至30之间,可以通过接近顶点(最高点)确定顶点的高度和距离,从而确定顶点大约为15、11。

     

    Section 3.3: Polynomial Functions
    ::第3.3节:多功能

    1. The real roots are -3, 2, and 3.

      ::真正的根是3,3,2,3
    2. The real roots are -5, -2, and 2.

      ::真正的根源是5 -2和2
    3. The real root is -1.
      lesson content

      ::真正的根是 -1
    4. The real root is 4.

      ::真正的根是4
    5. The real root is 1.

      ::真正的根是1
    6. One factor is ( x 3 ) .

      ::一个因素是 (x-3) 。
    7. One factor is ( x + 1 ) .

      ::一个因素是 (x+1) 。
    8. Factors are ( x 4 ) , ( x + 4 ) , and ( x + 2 ) .

      ::因素是(x-4)、(x+4)和(x+2)。
    9. There are no integer roots.

      ::没有整数根 。
    10. Factors are ( x + 7 ) , ( 2 x + 3 ) , and  ( x 1 ) .

      ::因素是(x+7)、(2x+3)和(x-1)。
    11. Zeros: 1 and approximately -2.343, -0.471, and 1.814
      End behavior: As  x  approaches ±∞,  y  approaches +∞.
      Sample test  points: (-1, -4),  (0, 2),  and (1.47, -1.195)

      ::零: 1 和 约 -2.343,-0.471 和 1. 814 最终行为: 作为 x 接近 , y 接近 。 抽样测试点sad 1 - 4, (0, 2) 和 (1.47, - 1. 195)
    12. Zeros: -3 and 1
      End behavior: As  x  approaches ±∞,  y  approaches +∞. 
      Sample test  points: (-4, 65),  (0, -3), and (2, 35)

      ::零: - 3 和 1 结束行为: 当 x 接近 , y 接近 。 抽样测试点sad 4, 65) , (0, 3) 和 (2, 35)
    13. Zeros: -2 and approximately 2.672
      End behavior: As  x  approaches ±∞,  y  approaches -∞. 
      Sample test  points: (-3, -63), (0, 6), and (3, -15)

      ::零: - 2 和 大约 2. 672 最终行为: 当 x 接近 , y 接近 - 。 抽样测试点sad 3 ) - 63, (0 , 6) 和 (3 , 15)
    14. Zeros: -3, -2, -1, and 1
      End behavior: As  x  approaches ±∞,  y  approaches -∞. 
      Sample test  points: (-2.607, 1.383), (1.469, -0.941), and (0, 6)

      ::零: -3, -2, -1 和 1 结束行为: 当 x 接近 , y 接近 - 。 抽样测试点sad 2. 607, 1. 383), (1.469, - 0.941) 和 ( 0, 6)
    15. Zeros: There are no real zeros.
      End behavior: As  x  approaches ±∞,  y  approaches -∞. 
      Sample test points: (-1, -3), (0, -4), and (1, -19)

      ::零: 没有真正的零。 结束行为 : x 接近 , y 接近 - 。 抽样测试点 sad 1 ) - 3 , (0 , - 4) 和 (1, -19)

     

    Section 3.4: Synthetic Division of Polynomials
    ::第3.4节:多边合成科

    1. x + 4  
      ::x+4 x+4
    2. x + 1  
      ::x+1 x+1
    3. a + 5  
      ::a+5 +5
    4. x + 2  
      ::x+2 x+2
    5.   x 2 + 4 x 1 + 12 x + 2  
      ::x2+4x- 1+12x+2
    6. 4 x 2 + 17 x + 16  
      ::4x2+17x+16
    7. 2 x 1 4 2 x + 1  
      ::2 - 1 - 42x+1
    8. 2 x 3 33 x 2 + 267 x 2 , 423 + 21 , 849 x + 9  
      ::2x3-33x2+267x-2,423+21,849x+9
    9. x 2 + 2 x 1  
      ::x2+2x- 1
    10. 3 x 4 + 3 x 3 + 7 x 2 + 7 x + 6 + 4 x 1  
      ::3x4+3x3+7x2+7x6+6+4x-1
    11. Numbers 6 and 9 have no remainder. Having no remainder means the divisor in synthetic division is a root.
      ::第6和第9号没有剩余部分。没有剩余部分,就意味着合成部分的断层是根。
    12. ( x k )  is a factor when  k  is a zero.  f ( k ) = 0  if and only if  k  is a zero.
      :sadx-k) 是指当 k 是 0 时的系数。 f(k)=0, 前提是 k 是 0 。
    13. a.  f ( - 2 ) = - 14  
      b. The remainder is - 14 , which is the same as  f ( - 2 )
      ::a. f(-2)=-14 b. 其余为-14,与f(-2)相同。
    14. x = - 4 , 1 6 , - 5 2  
      ::x=4-4、16-52
    15. x = 5 , ± 2  
      ::x=5,%2x=5,%2
    16. x = 2 , 1 3 , 1 2  
      ::x=2,13,12 x=2,13,12
    17. x = - 4 , - 4 , - 1 , 2  
      ::x=4、4、4、1、2
    18. x = - 2 , 0 , - 3 2 , 1 3  
      ::x=-2,0,-32,13
    19. The area of the base is  x 2 5 x 12.  
      ::基座区域为 x2-5x-12。
    20. D = 1 π 4 π h + 20 π h 2  
      ::D=14h+20h2

     

    Section 3.5: Real Zeros of Polynomials
    ::第3.5节:多元体实际零

    1. ± 1 , ± 2 , ± 4 , ± 5 , ± 10 , ± 20  
    2. ± 1 4 , ± 1 2 , ± 3 4 , ± 1 , ± 5 4 , ± 3 2 , ± 5 2 , ± 3 , ± 15 4 , ± 5 , ± 15 2 , ± 15  
    3. ± 1 2 , ± 1 , ± 2 , ± 4 , ± 8  
    4. ± 1 , ± 3 , ± 9  
    5. ± 1 8 , ± 1 4 , ± 3 8 , ± 1 2 , ± 3 4 , ± 1 , ± 3 2 , ± 2 , ± 3 , ± 4 , ± 6 , ± 8 , ± 12 , ± 24  
    6. x = 1 3 , 1 2 , 2  
      ::x=13,12,2
    7. x = - 4 , - 4 , - 1 , 2  
      ::x=4、4、4、1、2
    8. x = - 3 , 1 ± 2 4  
      ::x=3,124
    9. x = 3 2 ; other roots are complex  
      ::x=32;其他根复杂
    10. x = 5 ; other roots are complex  
      ::x=5;其他根复杂
    11. x = - 5 2 , 1 , 2 ± 7 3  
      ::x=-52,1,273
    12. x = - 4 ± 3 , - 3 , 2 , 2  
      ::x=43,3,3,2,2
    13. x = - 4 , - 4 , 3 2 , 3 2  
      ::x=4、4、32、32、32
    14. x = - 5 , - 1 3 , 1 3 , 5  
      ::x=5-5、13、13.5
    15. x = ± 21 3 . There are two real solutions. The other two solutions are imaginary.
      ::x213. 有两种真正的解决方案,其他两种解决方案是想象的。

     

    Section 3.6: Fundamental Theorem of Algebra
    ::第3.6节:代数基本理论


    1.   f ( x ) = ( x 2 ) 2 ( x 4 ) 3 ( x 1 ) ( x 2 i ) ( x + 2 i )       = x 8 17 x 7 + 118 x 6 438 x 5 + 984 x 4 1 , 512 x 3 + 1 , 760 x 2 1 , 408 x + 512  
      ::f(x) = (x) = (x-2) 2(x-4) 3(x-1)(x-2i)(x-2i)(x-2i)(x+2i) =x8-17x7+118x6-438x5+984x4-1,512x3+1,760x2-1,408x+512)

    2.   f ( x ) = ( x 1 ) ( x + 3 ) 3 ( x + 1 ) ( x 3 i ) ( x + 3 i )       = x 7 + 9 x 6 + 29 x 5 + 45 x 4 + 51 x 3 + 27 x 2 81 x 81  
      ::f(x) =(x- 1)(x+3)(x+1)(x-3i)(x-3i)(x+3i) =x7+9x6+29x5+45x4+45x4+51x3+27x2-81x-81)

    3. f ( x ) = ( x 5 ) 2 ( x + 1 ) 2 ( x 2 i ) ( x + 2 i )       = x 6 8 x 5 + 10 x 4 + 8 x 3 + 49 x 2 + 160 x + 100  
      ::f(x) = (x) = (x--5) 2(x+1) 2(x-2i)(x+2i) = x6-8x5+10x4+8x3+492+160x+100

    4.   f ( x ) = ( x i ) ( x + i ) ( x 2 i ) ( x + 2 i ) = x 4 + 3 x 2 + 2      
      :sadx)=(x-i)(x+i)(x-2i)(x+2i)=x4+3x2+2)
    5.   f ( x ) = ( x + 3 ) 2 ( x 2 ) ( x i ) ( x + i )  
       Roots are  - 3   ( m u l t i p l i c i t y   2 ) , 2 , i , - i
      ::f(x) = (x+3) 2(x-2)(x- i)(x+i) 根为 -3(多重2), 2, i, i, i
    6.   g ( x ) = ( x 1 ) ( x + 1 ) ( x i ) ( x + i )  
       Roots are  1 , - 1 , i , - i    
      ::g(x) = (x- 1) (x+1) (x-i) (x+1) (x-i) (x+i) 根为 1,-1,i,-i
    7.   h ( x ) = ( x 4 ) 2 ( x 2 ) 2 ( x + 3 i ) ( x 3 i )  
       Roots are  4   ( m u l t i p l i c i t y   2 ) , 2   ( m u l t i p l i c i t y   2 ) , - 3 i , 3 i  
      ::h(x) = (x- 4) 2(x-2) 2(x+3i)(x-3i) 根为 4(多重2) 2, (多重2) , 3i, 3i
    8.   j ( x ) = ( x 1 ) 2 ( x 3 ) 3 ( x + 3 i ) ( x 3 i )  
       Roots are  1   ( m u l t i p l i c i t y   2 ) , 3   ( m u l t i p l i c i t y   3 ) , - 3 i , 3 i  
      :sadx) j(x) = (x- 1) 2(x-3) 3(x+3i)(x-3i)(x-3i) 根为 1 (多重2) , 3 (多重3), 3i, 3i
    9.   k ( x ) = ( x 2 ) ( x + 3 ) ( x + 4 ) ( x 1 ) 2  
       Roots are  2 , - 3 , - 4 , 1   ( m u l t i p l i c i t y   2 )  
      ::k(x) = (x- 2) (x+3) (x+4) (x- 1) 2 根为 2, 3, 4, 1 (多重 2) 。
    10.   m ( x ) = ( x 2 ) ( x + 2 ) ( x 3 ) ( x + 3 ) ( x i ) ( x + i )  
       Roots are  2 , - 2 , 3 , - 3 , i , - i  
      :sadxx) = (x- 2) (x+2) (x- 3) (x+3) (x+3) (x- i) 根为 2, 2, 2, 3, 3, 3, i, i
    11.   n ( x ) = ( x 6 ) ( x + 1 ) 3 ( x 5 i ) ( x + 5 i )  
       Roots are  6 , - 1   ( m u l t i p l i c i t y   3 ) , 5 i , - 5 i  
      ::n(x) = (x-6)(x+1) 3 (x-5i)(x+5i) 根为 6-1 (多重 3) , 5i, 5i
    12.   p ( x ) = ( x 2 ) ( x + 2 ) 3 ( x 7 i ) ( x + 7 i )  
       Roots are  2 , - 2   ( m u l t i p l i c i t y   3 ) , 7 i , - 7 i  
      ::p(x) = (x-2)(x+2) 3(x-7i)(x+7i) 根为 2-2 (多重 3) , 7i, 7i
    13. The degree of the polynomial is the number of roots with multiplicity.
      ::多元度的程度是有多重性的根数。
    14. Multiplicity refers to a root that counts more than once, because when the polynomial is in factored form, the degree of its corresponding binomial is greater than 1.
      ::多重性是指一个不止一次的根,因为当多元性以因数形式出现时,其相应的二元性的程度大于1。
    15.   - 3 i  
      ::-3i -3i

     

    Section 3.7: Approximating Real Zeros of Polynomial Functions
    ::第3.7节:多元函数接近实际零

    1. a) Leading coefficient: 3; Degree: 5
      b) 1 real zero at approximately -1.4
      c)  4 imaginary zeros
      :sada) 主系数: 3; 度: 5b) 1个实际零,约1.4c) 4个假想零
    2. a) Leading coefficient: -1; Degree: 3
      b) 1 real zero at approximately 2
      c) 2 imaginary zeros
      :sada) 主系数:-1;度:3b) 1实际零,约2c) 2想象零
    3. a) Leading coefficient: 1/2; Degree: 4
      b) 2 real zeros at approximately -6.3 and -1
      c) 2 imaginary zeros
      :sada) 主系数:1/2; 度: 4b) 2个实际零点,约-6.3和-1c) 2个想象零
    4. a) Leading coefficient: 1; Degree: 5
      b) 5 real zeros at approximately -2.6 (multiplicity 2), -1, and 2.6 (multiplicity 2)
      c) 0 imaginary zeros
      :sada) 主系数:1;第1级:5b)5个实际零点,约-2.6(多重2)、-1和2.6(多重2)、c)0个想象零
    5. a) Leading coefficient: 1; Degree: 4
      b) 4 real zeros at approximately -1 and 3 (multiplicity 3) 
      c) 0 imaginary zeros 
      :sada) 主系数:1;第1级:4b)4个实际零点,大约为-1和3(多重3)c)0个想象零;
    6. [-2, -1]
    7. [-1, 3]
    8. [-2, 4]
    9. [-2, 2]
    10. The Bounded Roots Theorem is based on continuous functions, and this rational function is discontinuous at x = -3.5.
      ::断开根定理基于连续函数, 这个理性函数在 x = - 3. 5 时不连续 。
    11. [0.3125, 0.34375], Zero: 0.338
      ::[0.3125,0.34375],零:0.338
    12. [1.875, 1.9375], Zero: 1.893
      ::[1875, 1.9375], 零: 1.893

      

    Section 3.8: Rational Functions
    ::第3.8节:合理职能

    1. VA: x = -4, x= -2; HA: y = 0
      ::VA: x = 4, x = - 2;HA: Y = 0
    2. VA: x = -5; SA: y = x-5
      ::VA: x = - 5; SA: y = x 5
    3. VA: x = 3; SA: y = x+3
      ::VA: x = 3; SA: y = x+3
    4. x-intercepts: (-2, 0) and (2, 0)
      ::x 拦截sad-2,0)和(2,0)
    5. x-intercept: (0, 0)
      ::x 拦截: (0, 0)
    6. VA: x = -3, x = 4; HA: y = 0; Intercepts: (0, -1/12), (-1, 0)

      ::VA: x = - 3, x = 4;HA: y = 0;拦截: (0, 1/12), (-1, 0)
    7. VA: x = 3; SA: y = x + 6; Intercepts: (0, 10/3), (2, 0), (-5, 0)

      ::VA: x = 3; SA: y = x + 6; 拦截: (0, 10/3), (2, 0), (5, 0)
    8. VA: x=-2; SA: y = -8x^2+8x-14 Intercepts: approximately (0.81, 0) and (0, 4)


      ::VA: x= 2; SA: y= - 8x2+8x14 截取器: 大约(0. 81, 0) 和 (0, 4)
    9. VA: x = -5/3; SA: y = 2/3x -10/6; Intercepts: (0, -2/5), (1, 0), (-1, 0)

      ::VA: x = - 5/3; SA: y= 2/3x - 10/6; 拦截: (0, - 2/5), (1, 0), (1, 0)
    10. VA: x = 2, x = -7; SA: y = -2x + 12 Intercepts: approximately (2.285, 0); (0, -1/7)   


      ::VA: x = 2, x = -7; SA: y = - 2x + 12 截取器: 大约 (2.285,0); (0, - 1/7)
    11. VA: x= 1/2, x= -1, x = 3; HA: y = 0; Intercepts: (0, -10), (5, 0), (-6, 0)

      ::VA: x= 1/2, x=-1, x = 3;HA: y = 0;拦截: (0, - 10), (5, 0), (6, 0)
    12. VA: x = 0; HA: y = 7 Intercepts: approximately (-0.87, 0), (-0.47, 0), and (1.05, 0); no y-intercept   


      ::VA:x=0;HA:y=7拦截:约(-0.87,0),(-0.47,0)和(1.05,0);无y-拦截
    13. VA: x = -6, x = 1; HA: y = 0; Intercepts: (0, -5/6), (-5/2, 0)

      ::VA: x = - 6, x = 1;HA: y = 0;拦截: (0,-5/6), (-5/2, 0)
    14. VA: x = 3; SA: y = -1/2x; Intercepts: (0, -2/3), (-1, 0), (4, 0)

      ::VA: x = 3; SA: y = - 1/2x; 拦截: (0, - 2/3), (-1, 0), (4, 0)
    15. If we divide,  3 x 2 x 10 3 x + 5 = x 2.  This can also be found by factoring the numerator and denominator, and canceling the like factor of  3 x + 5 . This creates a hole,  not an asymptote. 

      ::如果我们分隔, 3x2- x- 103x+5=x-2, 也可以通过乘以分子和分母, 并取消类似因数 3x+5 来找到。 这会造成一个洞, 而不是一个小洞 。

    16. lesson content

     

    Section 3.9: Analysis of Rational Functions
    ::第3.9节:合理职能分析

    1.   y = ( x 2 ) ( x + 5 ) x 2 ; x 2
      ::y= (x- 2) (x+5) x-2; x2
    2.   y = ( x + 6 ) ( x 4 ) x 4 ; x 4  
      ::y= (x+6)(x- 4) x- 4; x4
    3.   f ( x ) = ( x 8 ) ( x 4 ) x 4 ; x 4  
      :sadxx) = (x-8) (x-4) x-4; x4
    4.   f ( x ) = ( x + 3 4 ) ( x + 4 5 ) x + 4 5 ; x - 4 5
      ::f(x) = (x+34)(x+45) x+45; x- 45
    5. y = ( x + 6 ) ( x + 7 ) x + 7 ; x - 7  
      ::y= (x+6)(x+7) x+7; x+7
    6. Asymptotes: VA: x = 1; SA: x^2+6x+9
      Holes: none
      Intercepts: approximately (-4.7, 0), (0, -7)
      Sketch: x 3 + 5 x 2 + 3 x + 7 x 1  

      ::微粒: VA: x = 1; SA: x2+6x+9 洞: 无拦截: 大约( 4.7, 0, 0, 7) 箭头: x3+5x2+3x+3x+7x-1
    7. Asymptotes: VA: x=0; SA: y=9x
      Holes: none
      Intercepts: none
      Sketch: ( 9 x 2 + 6 ) x  

      ::单位数: VA: x=0; SA: y=9x洞: 无截取数: 无折叠数: (9x2+6)x
    8. Asymptotes: VA: x = -3/2; HA: y = 0
      Intercepts: (0, 1/3), there is no x-intercept
      Hole: (7, 1/17)


      ::单位数: VA: x = - 3/2; HA: y = 0 拦截: (0, 1/3), 没有 x 拦截洞: (7, 1/17)
    9. Asymptotes: VA: x = -2, x = 2; SA: y = 5x – 9
      Holes: none
      Intercepts: approximately (-0.68, 0), (0.12, 0); (0, -0.25)
      Sketch:  5 x 3 9 x 2 7 x + 1 x 2 4
       
      ::微粒: VA: x = - 2, x = 2; SA: y = 5x - 9 孔: 无截取器: 大约( -0. 68, 0, 0, 0, 0, 0, 0. 12, 0; (0, 0,-0. 25); 缓存器: 5x3 - 9x2 - 7x+1x2 - 4)
    10. No asymptotes
      Intercepts: (0, -5), (5, 0)
      Hole (-6, -11)


      ::无空位拦截: (0, -5, (5, 0) 洞口 (6, - 11)
    11. Asymptotes: VA: x = -2; SA: y = 4x – 14
      Holes: none
      Intercepts: approximately ( -1.4, 0); (0, 7/4)
      Sketch:  4 x 3 + 2 x 2 + 7 ( x + 2 ) 2  

      ::微粒: VA: x = - 2; SA: y = 4x - 14洞: 无截取器: 大约( -1.4, 0); (0, 7/4) 缓存器: 4x3+2x2+7( x+2) 2
    12. Asymptotes: VA: x = 2; SA: y = x + 3 
      Intercepts (0, 0), (-1, 0)
      Hole: (3, 12)


      ::微粒: VA: x = 2; SA: y = x x + 3 拦截( 0, 0, 0, 1, 0) 洞口sad 3, 12)
    13. Asymptotes: VA: x = 0; SA: y = -6x+8
      Holes: none
      Intercepts: approximately (1.73, 0); no y-intercept
      Sketch:  - 6 x 3 + 8 x 2 + 7 x 2  

      ::单位数: VA: x = 0; SA: y = - 6x+8 孔: 无截取器: 大约( 1. 73, 0 ); 没有 y 截取线: - 6x3+8x2+7x2
    14. Asymptotes: VA: none; HA: y = -5
      Holes: none
      Intercepts: no x-intercept; (0, -5/2)
      Sketch:  - 5 x 2 2 x 5 x 2 + 2  

      ::单位数: VA: 无; HA: y = - 5洞: 无拦截: 没有 X 拦截; (0, - 5/2) 折叠: - 5x2 - 2x - 5x2+2
    15. Asymptotes: VA: x = cubic root of 2, or approx. 1.26; HA: y = 0
      Holes: none
      Intercepts: (1 , 0); (0, 1/2)
      Sketch: x 1 x 3 2  

      ::单位数: VA: x = 2 的立根或约1. 26; HA: y = 0 孔: 无截取器(1, 0); (0, 1, 1/2) 缓存器: x-1x3 - 2

     

    Section 3.10: Polynomial and Rational Inequalities
    ::第3.10节:多元和合理不平等

    1. - 3 x 1  
      ::- 3x1
    2. x < 1 3   o r   x > 2  
      ::x13 或 x2
    3. - 5 2 x 1 3  
      ::-52x13号
    4. x < 1 5   o r   x > 2  
      ::x15 或 x2
    5. x < 0   o r   x > 1 2  
      ::x0 或 x>12
    6. - 1 2 < x < 0   o r   x > 3 2  
      ::-12 <x <0 或 x>32
    7. - 2 < x < 0   o r   0 < x < 2  
      ::-2 <x <0 或 0 <x <2
    8. - 1 2 x 1 2   o r   x 2  
      ::- 12x=12 或 x=2
    9. - 3 < n < - 1   o r   1 < n < 2  
      ::-3<n<<-1或1<n<2
    10. - 3 n - 2   o r   2 n < 5  
      ::-n-2 或 2n<5
    11. n - 3   o r   - 5 2 n < 1 3   o r   n 3  
      ::n-3 或 -52n<13 或 n3
    12. n < - 3 2   o r   - 4 3 < n < - 1 2   o r   n > 1 2  
      ::n <-32 或 -43 <n < 12 或 n>12
    13. 0 t 36.490  
      ::036.490
    14. x 4.567   o r   - 1.294 x 1.861  
      ::x4.567 或 - 1.294x_1.861
    15. - 4.667 < x < 4.044   o r   5.000 < x < 6.623  
      ::-4.667 <x<4.044或5.000 <x<6.623
    16. y > 3 x 2 , x - 2 3  
      The graph would be as follows, with missing values anywhere  x = - 2 3

      ::y>3x-2,x% 23 图表如下,在 x= 23 处缺少值 :
    17. a)  R 2 < 60 , so 60 ohms is the max resistance. 
      b)  20 ohms, based on how the 2nd resistor would cancel out in this equation.
      :sada) R2<60,所以60 ohms是最大阻力。 (b) 20 ohms,基于第二抵抗者如何在这个方程式中取消。
    18. Width is greater than 4. 
      ::宽度大于4。