Module 8 Day 3 Practice

Module 8 Day 3 Practice

#1 and #6 Students Earn EC for the assignment today which is the EdPuzzle Practice afterward :)

Multiple Select

f(x) = ax² + bx + c

Which statements are true about this form of the quadratic function?

{mark all that apply}

• It is standard form

• It is factored form

• (0,c) indicates the y-intercept

• +a or -a tells us its opening direction

Multiple Select

f(x) = a(x - r₁)(x - r₂ )

Which statements are true about this form of a quadratic function?

{mark all that apply}

• It is standard form

• Zeroes are (r ₁ , ) and (r ₂ , 0)

• Zeroes are (- r ₁ , ) and (- r ₂ , 0)

• -a and +a tell the direction it opens

Multiple Select

f(x) = 5x² - 2x - 3

Convert to factored form to identify all true statements

• Parabola opens upward

• Parabola opens downward

• Contains (-3/5, 0) and (1,0)

• Contains (0,-3)

• Contains ( 3/5, 0) and (-5, 0)

5x² - 2x - 3

Use the Big X to factor

• Factored: (5x + 3)(x - 1)

• Solutions are -3/5 and 1 which means

• Points on the graph are zeros at (-3/5,0) and (1,0)

Multiple Choice

f(x) = 3x² + 8x - 2

Which of the following are correct?

{read the choices carefully as they have a lot of similarities!}

• The parabola opens upward and contains (-2, 0)

• The parabola opens downward and contains (-2, 0)

• The parabola opens upward and contains (0, -2)

• The parabola opens downward and contains (0, -2)

f(x) = 3x² + 8x - 2

• This is standard form, so:

• Lead or "a" coefficient is +3, so it opens upward

• "c" coefficient is -2, so y-intercept is -2 which is (0, -2) as a coordinate

Multiple Select

g(x) = - 4x² + 100

Convert to factored form to identify all true statements.

*hint, a GCF of -4 must be factored out first*

• the parabola opens upward

• the parabola opens downward

• contains (10, 0) and (-10,0)

• contains (5, 0) and (-5, 0)

• contains (5/2, 0) and ( -5/2, 0)

- 4x² + 100

factor out -4 to get -4(x² - 25).....use DOTS

• Factored is -4(x + 5)(x - 5)

• Solved, x = -5 or 5 which means

• zeros are points on the parabola at (-5,0) and (5,0)

Multiple Choice

f(x) = -2x² - 10x + 7

Which of the following is correct?

{read the choices carefully as they have a lot of similarities!}

• The parabola opens upward and contains (0, 7)

• The parabola opens downward and contains (0, 7)

• The parabola opens upward and contains (7,0)

• The parabola opens downward and contains (7,0)

-2x² - 10x + 7

• This is standard form, so:

  
  

• Lead or "a" coefficient is -2, so it opens downward

• "c" coefficient is +7, so y-intercept is 7 which is (0, 7) as a coordinate

The End

You now have a Practice EdPuzzle to continue working with Standard and Factored Forms of Quadratic Functions :)