Answer:
Blue: y = x²
Red: y = -x² + 18
Step-by-step explanation:
The blue parabola opens upwards, therefore the term in x² is positive.
The red parabola opens downwards, therefore the term in x² is negative.
The x-value of the vertices of both parabolas is x = 0.
Therefore, the equations of both parabolas will not have a term in x.
The y-intercept of the blue parabola is also the y-value its vertex: y = 0.
The y-intercept of the red parabola is also the y-value its vertex: y = 18.
Therefore, the equation for each parabola is:
- Blue: y = x²
- Red: y = -x² + 18
To check, substitute x = ±3 into both equations:
Blue
[tex]x=3 \implies y=(3)^2=9[/tex]
[tex]x=-3 \implies y=(-3)^2=9[/tex]
Red
[tex]x=3 \implies y=-(3)^2+18=9[/tex]
[tex]x=-3 \implies y=-(-3)^2+18=9[/tex]
