"

Quadratic Functions

Prep for Graphing Quadratic Functions

    1. [latex]\begin{array}{lc}B&\left(0,1\right)\\F&1\\C\;or\;D\;\;&x=1\\C\;or\;D&x=1\\A&\left(1,0\right)\\E&y=1\end{array}[/latex]
    1. [latex]y=3[/latex]
    2. [latex]x=3[/latex]
    3. [latex](-3,0)[/latex]
    1. Explain
    2. [latex]-4[/latex]
    3. [latex]-\frac32[/latex]
    4. [latex]4[/latex]
      1. [latex]-\frac56[/latex]
      2. [latex]\frac12[/latex]
      3. [latex]-10[/latex]
      1. [latex]57[/latex]
      2. [latex]5[/latex]
      3. [latex]\frac{19}2[/latex]
      1. [latex]-26[/latex]
      2. [latex]-2[/latex]
      3. [latex]4[/latex]
      1. [latex]-13[/latex]
      2. [latex]-\frac{89}{16}[/latex]
      3. [latex]-\frac{41}4[/latex]
    1. An intercept is a point where a graph touches the x- or y-axis.
      1. y-intercept: (0, 2); x-intercept: (-5, 0)
      2. y-intercept: (0, -2); x-intercepts: (-2, 0), (1, 0)
      1. Yes
      2. No
    1. Infinity and negative infinity; Discuss with classmates.

Graphing Quadratic Functions

    1. 1
    2. none
    3. 1
  1. Graph A
    1. [latex]x=3[/latex]
    2. [latex](3,4)[/latex]
    3. maximum
    4. Domain [latex]=\left(-\infty,\infty\right);[/latex] Range [latex]=(-\infty,4\rbrack[/latex]
    5. [latex](0,-5)[/latex]
    6. The points are symmetric across the axis of symmetry.

    Graph B

    1. [latex]x=-2[/latex]
    2. [latex](-2,-5)[/latex]
    3. maximum
    4. D [latex]=\left(-\infty,\infty\right);[/latex] R [latex]=\lbrack-5,\infty)[/latex]
    5. [latex](0,-1)[/latex]
    6. The points are symmetric across the axis of symmetry.
    1. Upaxis of symmetry: [latex]x=3[/latex]

      vertex: [latex](3,4)[/latex]

      y-intercept: [latex](0,13)[/latex]

      x-intercepts: none

      Domain : [latex]\left(-\infty,\infty\right)[/latex]

      Range: [latex]\lbrack4,\infty)[/latex]

    2. Downaxis of symmetry: [latex]x=-1[/latex]

      vertex: [latex](-1,0)[/latex]

      y-intercept: [latex](0,-1)[/latex]

      x-intercepts: 1

      Domain : [latex]\left(-\infty,\infty\right)[/latex]

      Range: [latex](-\infty,0\rbrack[/latex]

    3. Downaxis of symmetry: [latex]x=2[/latex]

      vertex: [latex](2,7)[/latex]

      y-intercept: [latex](0,3)[/latex]

      x-intercepts: 2

      Domain : [latex]\left(-\infty,\infty\right)[/latex]

      Range: [latex](-\infty,7\rbrack[/latex]

    4. Downaxis of symmetry: [latex]x=-5[/latex]

      vertex: [latex](-5,-7)[/latex]

      y-intercept: [latex](0,-82)[/latex]

      x-intercepts: none

      Domain : [latex]\left(-\infty,\infty\right)[/latex]

      Range: [latex](-\infty,-7\rbrack[/latex]

Homework: Graphing Quadratic Functions

  1. Explain.
  2. Upaxis of symmetry: [latex]x=-5[/latex]

    vertex: [latex](-5,1)[/latex]

    y-intercept: [latex](0,26)[/latex]

    x-intercepts: none

    Domain : [latex]\left(-\infty,\infty\right)[/latex]

    Range: [latex]\lbrack1,\infty)[/latex]

  3. Downaxis of symmetry: [latex]x=2[/latex]

    vertex: [latex](2,8)[/latex]

    y-intercept: [latex](0,0)[/latex]

    x-intercepts: 2

    Domain : [latex]\left(-\infty,\infty\right)[/latex]

    Range: [latex](-\infty,8\rbrack[/latex]

    Explain.

  4. Downaxis of symmetry: [latex]x=-4[/latex]

    vertex: [latex](-4,0)[/latex]

    y-intercept: [latex](0,-16)[/latex]

    x-intercepts: 1

    Domain : [latex]\left(-\infty,\infty\right)[/latex]

    Range: [latex](-\infty,0\rbrack[/latex]

    Explain.

  5. Downaxis of symmetry: [latex]x=-1[/latex]

    vertex: [latex](1,-2)[/latex]

    y-intercept: [latex](0,-3)[/latex]

    x-intercepts: none

    Domain : [latex]\left(-\infty,\infty\right)[/latex]

    Range: [latex](-\infty,-2\rbrack[/latex]

  6. Upaxis of symmetry: [latex]x=-4[/latex]

    vertex: [latex](4,-2)[/latex]

    y-intercept: [latex](0,30)[/latex]

    x-intercepts: 2

    Domain : [latex]\left(-\infty,\infty\right)[/latex]

    Range: [latex]\lbrack-2,\infty)[/latex]

  7. Answers may vary.

Prep for Applications of Quadratic Functions

      1. meters per second
      2. 58.8 m
      3. [latex]D\left(t\right)=-4.9t^2+19.6t+58.8[/latex]
      4. The distance from the ground in meters
      5. When does the object strike the ground?
      1. feet per second
      2. height above the ground
      3. feet
      4. time
      5. seconds
      6. the graph is a parabola opening down.
      1. seconds
      2. meters
      3. seconds
      1. feet
      2. seconds
    1. Discuss.
    1. exact
    2. approximate
    3. exact
    4. approximate
    5. exact
    6. approximate
    1. [latex]=[/latex]
    2. [latex]\approx[/latex]
    3. [latex]\approx[/latex]
    4. [latex]=[/latex]
    5. [latex]\approx[/latex]
    6. [latex]\approx[/latex]
    7. [latex]\approx[/latex]
    8. [latex]=[/latex]
    9. [latex]\approx[/latex]
    1. [latex]3,600[/latex]
    2. [latex]45[/latex]
    3. [latex]39.82[/latex]
    4. [latex]72.49[/latex]
    5. [latex]-3.094[/latex]
    6. [latex]0.3[/latex]
    7. [latex]0.3[/latex]
    8. [latex]0.59[/latex]

Applications of Quadratic Functions

    1. 8 sec
    2. 256 ft
      1. 192 ft
      2. Up
      1. 192 ft
      2. Down
    3. 1 second, 7 seconds
    4. from 0 to 1 because it covered more distance.
    5. Domain [latex]=\left[0,8\right][/latex]; Range [latex]=\left[0,256\right][/latex]
    1. [latex](0,0)[/latex]
    2. Discuss
    3. Discuss
    4. x-intercept is used for domain; vertex is used for range
    1. x y
      0 23
      3 311
      6 311
      9 23
      10 −137
    2. 23 ft
    3. 311 ft
    4. 347 ft
    5. between 9 and 10 secs
    1. 2 meters
    2. [latex]2.30625[/latex] meters
    3. The ball is never above 3 meters
  1. The skateboarder is about 0.86 ft above the ground at the bottom of the half-pipe. The bottom of the half-pipe is 6.75 ft away from the starting point of the ride.
    1. 25 feet
    2. 25 feet at [latex]t=0[/latex]
    1. No, the maximum height is [latex]12.25[/latex] feet.
    2. 6 feet

Homework: Applications of Quadratic Functions

    1. x y
      0 80
      1 124
      2 136
      3 116
      4 64
      5 −20
    2. 80 ft
    3. 134 ft
    4. 136.25 ft
    5. between 4 and 5 seconds
    1. 8 feet
    2. 0.625 seconds
    3. 14.25 feet
    1. [latex](0, 0)[/latex]
    2. Discuss
    3. Discuss
    4. x-intercept is used for domain; vertex is used for range
    5. Answers may vary
    1. 33 feet
    2. 0.375 seconds
    3. 35.25 feet
    1. There are 4,540 parking spaces at 7 A.M.
    2. There are only 40 parking spaces at 10 A.M.
  1. The maximum height is 52 meters at time [latex]t=0[/latex]

Prep for Solving Using Quadratic Formula

    1. 5
    2. 10
    3. [latex]\sqrt{889}[/latex]
    4. Discuss with a classmate
    1. [latex]2\sqrt{3}[/latex]
    2. [latex]6\sqrt{2}[/latex]
    3. [latex]\frac{7 \pm \sqrt{3}}{2}[/latex]
    4. [latex]-1, 7[/latex]
    5. [latex]1 \pm \sqrt{5}[/latex]
    6. [latex]\frac{5\pm\sqrt5}2[/latex]
    1. [latex]6i[/latex]
    2. [latex]6i\sqrt{2}[/latex]
    3. [latex]\frac{2}{5}i[/latex]
    4. [latex]-3 \pm \frac{3}{2}i[/latex]
    5. [latex]\frac{5}{2} \pm \frac{3\sqrt{2}}{2}i[/latex]
    6. [latex]2 \pm 3i[/latex]

Solving Using the Quadratic Formula

    1. [latex]x = 2 \pm \sqrt{7}[/latex]
    2. [latex]x = \pm i\sqrt{3}[/latex]
    3. [latex]x = \frac{-5 \pm \sqrt{33}}{2}[/latex]
    4. [latex]x = \frac{3}{2} \pm \frac{\sqrt{11}}{2}i[/latex]
    5. [latex]x = -3[/latex]
    6. [latex]x = \frac{3 \pm \sqrt{13}}{4}[/latex]
    7. [latex]x = \frac{3 \pm \sqrt{29}}{10}[/latex]
    8. [latex]x = \frac{7}{2} \pm \frac{\sqrt{23}}{2}i[/latex]
    9. [latex]x = \pm \frac{5}{2}i[/latex]
    10. [latex]x = 4, -\frac{1}{2}[/latex]
    11. [latex]x = \frac{-1 \pm \sqrt{11}}{4}[/latex]
    12. [latex]x = \frac{9}{2}, 0[/latex]
    1. 2
    2. 1
    3. none
    4. Discuss.
    5. Check with your classmate.
    1. axis of symmetry: [latex]x=1[/latex]; (1,3); y-intercept: (0,1); x-intercepts: [latex]\left(\frac{2\pm\sqrt6}2,0\right)[/latex]Domain: [latex]\left(-\infty,\infty\right)[/latex]; Range: [latex](-\infty,3\rbrack[/latex]
      1. 293 feet
      2. 329 feet
      3. 2 seconds, 7 seconds
      4. 9.03 seconds
      5. Domain [latex]=[0,9.03][/latex]; Range [latex]=0,329[/latex]

Homework: Solving Using the Quadratic Formula

    1. [latex]5\sqrt{7}[/latex]
    2. [latex]3 \pm \frac{\sqrt{3}}{2}[/latex]
    3. [latex]10i\sqrt{3}[/latex]
    4. [latex]5 \pm \frac{i\sqrt{30}}{2}[/latex]
    1. [latex]x = \frac{7}{2}, -\frac{5}{3}[/latex]
    2. [latex]x = \frac{17}{20}, -\frac{10}{29}[/latex]
    3. [latex]x = \frac{5 \pm \sqrt{109}}{6}[/latex]
    4. [latex]x = \pm \frac{\sqrt{2}}{4}[/latex]
    5. [latex]x = 4 \pm \sqrt{6}[/latex]
    6. [latex]x = -\frac{3}{4} \pm \frac{\sqrt{51}}{4}i[/latex]
    7. [latex]x = \frac{1}{3} \pm \frac{\sqrt{71}}{3}i[/latex]
    8. [latex]x = 1[/latex]
    9. [latex]x = \frac{5 \pm \sqrt{17}}{2}[/latex]
    10. [latex]x = 0, 2[/latex]
    11. Explain.
    12. Discuss.
    13. Check with a classmate.
    1. Down; axis of symmetry: [latex]x=3[/latex]; vertex: (3,3); y-intercept: (0,-15); x-intercepts: [latex]\left(\frac{6\pm\sqrt6}2,0\right);[/latex] Domain: [latex]\left(-\infty,\infty\right)[/latex]; Range: [latex](-\infty,3\rbrack[/latex]
    1. 1.57 seconds
    2. 1.45 seconds
    3. [latex]\approx10.32[/latex] seconds longer
      1. 2 seconds
      2. 382 feet
      3. Domain [latex]=[0,4.763][/latex]; Range [latex]=[0,382][/latex]

Solving Quadratic Equations Using Square Root Method

    1. [latex]x = \pm 4[/latex]
    2. [latex]x = \pm 10[/latex]
    3. [latex]x = \pm 5i[/latex]
    4. [latex]x = \pm 9i[/latex]
    5. [latex]x = \pm i\sqrt{3}[/latex]
    6. [latex]x = \pm i[/latex]
    7. [latex]x = \pm \sqrt{15}[/latex]
    8. [latex]x = \pm \frac{3\sqrt{11}}{2}[/latex]
    9. [latex]x = \pm 4[/latex]
    10. [latex]x = \pm \frac{2\sqrt{2}}{7}i[/latex]
    11. [latex]x = \pm 2\sqrt{3}[/latex]
    12. [latex]x = \pm \sqrt{41}[/latex]
    13. [latex]x = \pm \sqrt{3}[/latex]
    14. [latex]x = \pm \sqrt{23}[/latex]
    15. [latex]x = \pm 8[/latex]
    16. [latex]x = \pm \frac{2}{3}i[/latex]
    1. 1.25 seconds
    2. [latex]x=\pm\frac{\sqrt5}3[/latex]
    3. Explain.
    4. Discuss.

Homework: Solving Quadratic Equations Using Square Root Method

  1. Many answers possible.
    1. [latex]x = \pm 7[/latex]
    2. [latex]x = \pm \sqrt{3}[/latex]
    3. [latex]x = \pm 2i[/latex]
    4. [latex]x = \pm \frac{9}{2}i[/latex]
    5. [latex]x = \pm \sqrt{46}[/latex]
    6. [latex]x = \pm 2\sqrt{7}[/latex]
    1. Up; axis of symmetry: [latex]x=0[/latex]; vertex:[latex](0,-5)[/latex]; y-intercept: [latex](0,-5)[/latex]; x-intercepts: [latex]\left(\pm\frac{\sqrt5}2,0\right)[/latex]; Domain:[latex]\left(-\infty,\infty\right)[/latex]; Range: [latex]\lbrack-5,\infty)[/latex]
    1. 3.26 seconds
    2. Answers may vary
    3. Many answers possible.

Prep for Solving Equations by Factoring

    1. [latex]10(y^2 + 1)[/latex]
    2. [latex]3t(t + 2)[/latex]
    3. [latex]3x^2(5 - 7x^3)[/latex]
    4. [latex]6x^4(4 + 5x^3)[/latex]
    5. [latex]6(x^2 - 4x + 5)[/latex]
    6. [latex]2x(4x^2 + 6x - 5)[/latex]
    7. [latex](5x + 2y)(3z + 4)[/latex]
    8. [latex](6x^2 + 5)(4x - 7)[/latex]
    9. [latex]3x(x - 1)(y - 2)[/latex]
    10. [latex](3x - 2)(3y + 10x)[/latex]
    11. [latex]2(4x - 5)(7x + 3y)[/latex]
    12. [latex](4x - 5)(2y + 3)[/latex]
    1. [latex](x - 2)(x - 4)[/latex]
    2. [latex](x + 1)(x - 15)[/latex]
    3. [latex](x - 4)(x + 7)[/latex]
    4. [latex](x - 3)^2[/latex]
    5. [latex](x + 5)(x - 2)[/latex]
    6. [latex](x - 5)(x + 3)[/latex]
    7. [latex]7(x - 5)(x - 1)[/latex]
    8. [latex]3(x + 4)(x - 2)[/latex]
    9. [latex](2x - 1)(3x + 2)[/latex]
    10. [latex](5x - 4)(x - 2)[/latex]
    11. [latex](3x - 2)(x + 5)[/latex]
    12. Prime
    13. [latex](4x - 3)(2x + 3)[/latex]
    14. [latex](5x + 7)(2x + 1)[/latex]
    15. [latex](x - 2)(3x + 1)[/latex]
    16. [latex](3x - 2)(4x + 3)[/latex]
    1. [latex](x + 7)(x - 7)[/latex]
    2. [latex](2x + 9)(2x - 9)[/latex]
    3. Prime
    4. [latex]2x(4x + 1)(4x - 1)[/latex]
    5. [latex]25(x^2 + 4)[/latex]
    6. [latex](7 - x)(7 + x)[/latex]
    7. [latex]x(x + 1)(x - 1)[/latex]
    8. [latex]3x(x + 2)(x - 2)[/latex]

Solving Equations by Factoring

    1. [latex]x = \frac{4}{3}, -\frac{4}{3}[/latex]
    2. [latex]x = -7, -1[/latex]
    3. [latex]x = -3, -\frac{1}{2}[/latex]
    4. [latex]x = 3[/latex]
    5. [latex]x = -\frac{5}{2}, 0[/latex]
    6. [latex]t = -3, -6[/latex]
    7. [latex]x = 0, \frac{1}{2}[/latex]
    8. [latex]x = -2, \frac{3}{4}[/latex]
    9. [latex]x = -\frac{1}{5}, -\frac{8}{5}[/latex]
    10. [latex]x = -2, 2[/latex]
    11. [latex]x = 8, -8[/latex]
    12. [latex]t = \frac{7}{4}, -\frac{7}{4}[/latex]
    13. [latex]x = 2, \frac{3}{4}[/latex]
    14. [latex]x = -\frac{5}{3}, -\frac{6}{5}[/latex]
    15. [latex]x = 5, -\frac{7}{2}[/latex]
    16. [latex]t = \frac{3}{2}, -\frac{8}{3}[/latex]
    17. [latex]x = -\frac{3}{2}, \frac{25}{6}[/latex]
    18. [latex]x = \frac{2}{5}, \frac{1}{3}, 0[/latex]
    19. [latex]x = \frac{7}{3}, \frac{4}{3}[/latex]
    20. [latex]x = 0, -\frac{3}{4}, \frac{3}{2}[/latex]
    21. [latex]t = -\frac{1}{3}, \frac{2}{5}[/latex]
    22. [latex]x = -\frac{3}{4}, \frac{2}{3}[/latex]
    23. [latex]x = 3, \frac{2}{7}[/latex]
    24. [latex]x = -4, -\frac{1}{6}[/latex]
    25. [latex]x=-\frac49,\frac49[/latex]
    26. [latex]x = 2, -2[/latex]
    1. Up; axis of symmetry:[latex]x=-2[/latex]; vertex:[latex](-2,-8)[/latex]; y-intercept:[latex](0, 0),(-4, 0)[/latex]; Domain: [latex]\left(-\infty\right)[/latex]; Range: [latex]\lbrack-8,\infty)[/latex]
      1. 8 second, 7 seconds
      2. 1
    1. [latex]x=0,-3[/latex]
    2. Explain.

Homework: Solving Equations by Factoring

    1. [latex]x = -3, -5[/latex]
    2. [latex]t = \pm \frac{5}{2}[/latex]
    3. [latex]x = \frac{5}{3}, -\frac{3}{2}[/latex]
    4. [latex]x = 0, -10[/latex]
    5. [latex]t = -\frac{3}{2}[/latex]
    6. [latex]x = 6, -\frac{1}{4}[/latex]
    7. [latex]x = \frac{4}{3}[/latex]
    8. [latex]x = -\frac{4}{3}, 3[/latex]
    9. [latex]x = 0, -6, 2[/latex]
    10. [latex]x = -\frac{2}{3}, -\frac{4}{3}[/latex]
    11. [latex]x = 0, \frac{1}{5}[/latex]
    12. [latex]t = -3, -\frac{3}{2}[/latex]
    13. [latex]t = 4, \frac{3}{5}[/latex]
    14. [latex]x = 0, \pm \frac{3}{2}[/latex]
    15. [latex]x = -6, \frac{1}{4}, 0[/latex]
    16. [latex]x = -\frac{5}{2}, 1[/latex]
    17. [latex]x = 0, \frac{1}{4}[/latex]
    18. [latex]x = 5, -5[/latex]
    19. [latex]t = \frac{4}{5}, -\frac{2}{3}[/latex]
    20. [latex]x = -\frac{5}{2}, \frac{3}{4}[/latex]
    21. Answers may vary.
    1. Down; axis of symmetry: [latex]x=0[/latex]; vertex: [latex](0,1)[/latex]y-intercept: [latex](0,1)[/latex]; x-intercepts: [latex](-1,0),(1,0)[/latex]; Domain: [latex]\left(-\infty,\infty\right)[/latex]; Range: [latex](-\infty,1\rbrack[/latex]
      1. 1 seconds, 3 seconds
      2. 5 seconds
    1. Answers may vary.
    2. Explain.

License

College Algebra for Non-STEM Majors Copyright © by Amy Collins Montalbano. All Rights Reserved.