Quadratic Equations in Standard Form

What are coordinates of the vertex of a parabola often represented by?

• (x, y)

• (x₂, y₂)

• (h, k)

• (r₂, d₂)

When given 3 or more ordered pairs on a parabola, which of the following is a method you can use to find the equation in standard form?

• Make a table of values. Find the rate of change (slope) and y-intercept.

• On the calculator, use STAT-EDIT to enter the values into L₁ and L₂. Then go to STAT>CALC and choose "QuadReg" (option 5).

• 3 ordered pairs will not give you enough information to find the equation for the parabola.

Your teacher gives you an equation in vertex form and wants you to convert it to standard form. Which one of the following describes the steps in the correct order?

• 1- Distribute the "a" value.

  2- Square the expression in parentheses.

  3- Combine like terms.

• 1- Sketch the graph on the coordinate plane.

  2- Identify 2 ordered pairs.

  3- Use STAT-EDIT and STAT>CALC-Option 4 (LinReg)

• 1- Square the expression in parentheses.

  2- Combine Like Terms.

  3- Distribute the "a" value.

• 1- Square the expression in parentheses.

  2- Distribute the "a" value.

  3- Combine like terms.

Convert the equation from vertex form (shown) to standard form:

y = -3(x + 5)² - 4

Formula: y = ax² + bx + c

• y = 9x² - 15x + 21

• y = -3x² - 75x - 4

• y = 9x² + 90x + 221

• y = -3x² - 30x - 79

Which answer choice(s) below correctly show(s) an equation in vertex form and in its standard form? (There may be more than 1.)

• y = -3(x + 2)² + 3

  y = -3x² - 12x - 15

• y = 2(x + 5)² + 1

  y = 2x² + 20x + 51

• y = 0.5(x - 3)² - 6

  y = 0.5x² - 3x - 1.5

Which of the following statements are TRUE?

• The "a" value is positive.

• The y-intercept is positive.

• It has two zeros.

• The axis of symmetry is x = 1.

• The vertex is at (0, 5).

Find the y-intercept of f(x) = 2x²-2x + 1

• 2

• -2

• 1

• -1

Quadratic equations take the shape of a _______ when graphed.

• u- shaped line

• straight line

• wavey line/snaked

• circle/elliptical

What is the axis of symmetry for the following equation?
y=4x²-8x+9

• x=-8

• x=1

• x=-1

• x=2

Find the vertex of 
f(x) = -x² - 4x + 12.

• (-2, 16)

• (2, 0)

• (2, 4)

• (-2, 4)