5. Quadratic Inequalities
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Identify the coordinates of the vertex.
y=0.25(x+4)^2+3
The vertex of this parabola has coordinates (- 4,3). This means that we have h=- 4 and k=3. We can use these values to partially write our function. y=a(x-(- 4))^2+3 ⇕ y=a(x+4)^2+3 We can see in the graph that the parabola opens upwards. Thus, a will be a positive number. To find its value, we will use the given point that is not the vertex.
x= - 8, y= 7
Add terms
Calculate power
LHS-3=RHS-3
.LHS /16.=.RHS /16.
a/b=.a /4./.b /4.
Rearrange equation
Write as a decimal