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Identify the vertex, axis of symmetry, maximum, or minimum, domain and range of each function.

a. y = 2(x - 2)^2 + 5
b. f(x) = -(x - 1)^2 + 2
c. g(x) = -(x +4)^2
d. y = 1/3(x + 2)^2 - 1

User Ziconic
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1 Answer

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Answer: see below

Explanation:

The vertex form of a quadratic equation is: y = a(x - h)² + k where

  • "a" is the vertical stretch (positive = min [U], negative = max [∩])
  • (h, k) is the vertex
  • Axis of Symmetry is always: x = h
  • Domain is always: x = All Real Numbers
  • Range is y ≥ k when "a" is positive or y ≤ k when "a" is negative

a) y = 2(x - 2)² + 5

↓ ↓ ↓

a= + h= 2 k= 5

Vertex: (h, k) = (2, 5)

Axis of Symmetry: x = h → x = 2

Max/Min: "a" is positive → minimum

Domain: x = All Real Numbers

Range: y ≥ k → y ≥ 5

b) y = -(x - 1)² + 2

↓ ↓ ↓

a= - h= 1 k= 2

Vertex: (h, k) = (1, 2)

Axis of Symmetry: x = h → x = 1

Max/Min: "a" is negative → maximum

Domain: x = All Real Numbers

Range: y ≤ k → y ≤ 2

c) y = -(x + 4)² + 0

↓ ↓ ↓

a= - h= -4 k= 0

Vertex: (h, k) = (-4, 0)

Axis of Symmetry: x = h → x = -4

Max/Min: "a" is negative → maximum

Domain: x = All Real Numbers

Range: y ≤ k → y ≤ 0

d) y = 1/3(x + 2)² - 1

↓ ↓ ↓

a= + h= -2 k= -1

Vertex: (h, k) = (-2, -1)

Axis of Symmetry: x = h → x = -2

Max/Min: "a" is positive → minimum

Domain: x = All Real Numbers

Range: y ≥ k → y ≥ -2

User Made By FA
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