Quadratic functions and modeling

Practice sheet

Fresh questions from the whole chapter, to do on paper.

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  1. A tile pattern has 6, 9, 14 and 21 tiles in steps 1 to 4 (a square of tiles plus 5 extra). How many tiles are in step 10?
  2. For x=0,1,2,3,4x = 0, 1, 2, 3, 4 a function takes the values 5, 8, 13, 20, 29. What is the (constant) second difference?
  3. For whole numbers xx from 1 to 14, which quantity is a quadratic function of xx?
    1. The area of a square with side xx cm
    2. The perimeter of a square with side xx cm
    3. The number of cells after xx doublings
  4. Write (x+2)(x−3)(x + 2)(x - 3) in standard form ax2+bx+cax^2 + bx + c.
  5. Find the xx-intercepts of y=(x−6)(x+2)y = (x - 6)(x + 2).
  6. A quadratic with leading coefficient 1 crosses the xx-axis at x=9x = 9 and x=−4x = -4. Write it in factored form.
  7. What is the yy-intercept of y=2x2+1x+11y = 2x^2 + 1x + 11?
  8. Does the graph of y=−6x2+5x+2y = -6x^2 + 5x + 2 open up or down?
    1. Down, so it has a maximum
    2. Up, so it has a minimum
    3. It depends on 2
  9. A parabola crosses the xx-axis at x=−1x = -1 and x=3x = 3. What is the xx-coordinate of its vertex?
  10. What is the xx-coordinate of the vertex of y=3(x+1)2+4y = 3(x + 1)^2 + 4?
  11. What is the smallest value of y=(x−9)2−3y = (x - 9)^2 - 3?
  12. Write a quadratic with vertex (8,1)(8, 1) and leading coefficient 2, in vertex form.