Building Quadratic Functions to Describe Situations

How can you tell whether a parabola opens up or opens down by looking at the equation?

• The vertex tells you the direction of the opening

• The value of "a" tells you the direction of the opening. If a > 0, the graph opens up. If a < 0 the graph opens down.

• All parabolas open upward

• All parabolas open downward

Tags

CCSS.HSF-IF.C.7A

Does the equation open up or down? 
Y = -3x² +7x - 2

• up

• down

• Neither; it opens to the right.

• Neither; it opens to the left.

Tags

CCSS.HSF-IF.C.7A

How can you determine the y-intercept of the graph of a quadratic function?

• "c" is the constant and this will be the value of y when x = 0. The y-intercept is the point (0,c)

• Throw a dart at the y-axis and the point where it lands is the y-intercept

• Parabolas don't have a y-intercept

Tags

CCSS.HSF-IF.C.7A

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

• (1,0)

• (-2,0)

• (0,1)

• (0, -1)

Tags

CCSS.HSF-IF.C.7A

Find the y-intercept y = x² - 6x + 5

• (0, 8)

• (0, - 6)

• (5, 0)

• (0, 5)

Tags

CCSS.HSF-IF.C.7A

What is the y-intercept of this parabola?

• (−1, 3)

• (−3, 11)

• (−2, 5)

• (0, 5)

Tags

CCSS.HSF-IF.C.7A

Identify c of the following quadratic function:
y = x ² + 16x + 64

• 2

• 1

• 16

• 64

Identify b of the following quadratic function:
 y = 2x ² − 4x − 2

• 2

• 4

• -4

• -2

Identify c of the following quadratic function:
y = −x ² + 18x − 75

• 18

• 75

• -75

• -1

What is the green dot on this parabola called?

• vertex

• top of the mountain

• tip of the iceberg

• peak of the parabola