Unit 4b Review Day 1

Solve Using the Quadratic Formula
 x² + 4x - 40 = -8

• -10 & -4
• -4 & 10
• -8 & 4
• 8 & -4

In the equation
y = x² +5x +7, match each leading coefficient with its correct letter 

• a=0, b=5, c=7
• a=1, b=5, c=7
• a=7, b=5, c=1

• a = 2 , b = 3, c = -5

• a = 2, b = -3, c = 5

• a = 2, b = -3, c = -5

• a = -2, b = 3, c = 5

Solve Using the Quadratic Formula 
2x² + 7x - 15 = 0

• -1.5 or 5
• No Solution
• -5 or 1.5
• 0.7 or 5

Find the value of x using the quadratic formula, if a=2, b=2, and c=-12.

• 2 & -3

• -2 & -3

• -2 & 3

• 2 & 3

f(x) = (x - 5)² + 3

Which graph represents the quadratic function?

• 
• 
• 
• 

Answer explanation

Graph (x, y) point for vertex is (5, 3)

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X-value for vertex (5) must have opposite sign (-5) in function

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Y-value for vertex (3) must have same sign (3) in function

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f(x) = (x - 5)² + 3

Function and graph match

Which of the following quadratic functions has the vertex (2, 4)?

• f(x) = 4(x − 2)² + 4

• f(x) = 3(x + 2)² + 4

• f(x) = 2(x − 4)² + 2

• f(x) = 2(x + 4)² + 2

Answer explanation

Graph (x, y) point for vertex is (2, 4)

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X-value for vertex (2) must have opposite sign (-2) in function

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Y-value for vertex (4) must have same sign (4) in function

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f(x) = a(x - 2)² + 4

Function and graph match

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f(x) = 4(x − 2)² + 4

This is correct option

f(x) = 3(x − 5)² + 7

What is the vertex of the following quadratic function?

• (7, -5)

• (5, 7)

• (3, 5)

• (-5, 7)

Answer explanation

f(x) = 3(x − 5)² + 7

----- ----- ----- -----

You can graph the function to see the vertex is (5, 7), or you could interpret the function without graphing

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X-value for vertex (5) must have opposite sign (-5) in function

----- ----- ----- -----

Y-value for vertex (7) must have same sign (7) in function

----- ----- ----- -----

(5, 7) is the vertex point

f(x) = x² – 12x + 9

What is the vertex of the following quadratic function?

• (6, -27)

• (-12, 9)

• (12, -9)

• (-6, -27)

Answer explanation

f(x) = x² – 12x + 9

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You can graph the function to see the vertex is (6, -27)

f(x) = -3(x + 4)² + 2

Find the maximum or minimum of the graph of the quadratic function.

• Max: 2

• Min: 2

• Max: 4

• Min: 4

• Max: -4

Answer explanation

f(x) = -3(x + 4)² + 2

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Graph (x, y) point for vertex is (-4, 2)

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The y-value for the vertex is the maximum value on graph (the highest point)

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Max: y = 2