Core Connections Integrated III, 2015
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Core Connections Integrated III, 2015 View details
2. Section 2.3
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Exercise 137 Page 95

Practice makes perfect
a

Let's rewrite the function in graphing form by completing the square.

y=2x^2-8x+7
y=2* x^2-2* 4x+7
y=2(x^2-4x)+7
y=2(x^2-4x+(-4/2)^2)+7-2(-4/2)^2
y=2(x^2-4x+(-2)^2)+7-2(-2)^2
y=2(x^2-4x+2^2)+7-2(2)
y=2(x^2-2(x)(2)+2^2)+7-2(2)
y=2(x-2)^2+7-2(2)
y=2(x-2)^2+7-4
y=2(x-2)^2+3

Having rewritten the function in graphing form, we can identify the vertex and line of symmetry. y=2(x- 2)^2+ 3 [-1em] &Vertex: ( 2, 3) &Line of Symmetry: x_s= 2

b

Like in Part A, we will rewrite the equation in graphing form by completing the square.

y=5x^2-10x-7
y=5* x^2-5* 2x-7
y=5(x^2-2x)-7
y=5(x^2-2x+(-2/2)^2)-7-5(-2/2)^2
y=5(x^2-2x+(-1)^2)-7-5(-1)^2
y=5(x^2-2x+1^2)-7-5(1)^2
y=5(x^2-2(x)(1)+1^2)-7-5(1)
y=5(x-1)^2-7-5(1)
y=5(x-1)^2-7-5
y=5(x-1)^2-12

Having rewritten the function in graphing form, we can identify the vertex and line of symmetry. y=5(x- 1)^2 - 12 [-1em] &Vertex: ( 1, -12) &Line of Symmetry: x_s= 1