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Y = 2(x+2)^2 - 18Find the x intercepts

User Cadaniluk
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1 Answer

3 votes

Answer

x=-5

and

x=1

Step-by-step explanation

The equation y = 2(x+2)^2 - 18 corresponds to a translation 2 units left and 18 units down, and a and a shrinkage about the x-axis with factor 2.

Making these transformations to y=x^2, we have:


y=2(x+2)^2-18
y=2(x{}^2+4x+4)-18
y=2x^2+8x+8-18
y=2x^2+8x-10

Factoring:


y=2(x^2+4x-5)
y=2(x+5)(x-1)

The x-intercept are found when y=0, that is:


\begin{gathered} x+5=0 \\ x=-5 \end{gathered}

and


\begin{gathered} x-1=0 \\ x=1 \end{gathered}

Y = 2(x+2)^2 - 18Find the x intercepts-example-1
User Liuyu
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3.4k points