Determine whether the relations represent y as a function of x.
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Answer:
Both of those are functions.
Step-by-step explanation:
[tex]y=x^2[/tex] is a parabola that opens up.
Any upward or downward parabola is a function because they pass the vertical line test.
[tex]x=\pm \sqrt{1-y}{/tex]
Square both sides:
[tex]x^2=1-y[/tex]
Subtract 1 on both sides:
[tex]x^2-1=-y[/tex]
Multiply both sides by -1:
[tex]-x^2+1=y[/tex]
So this is a another parabola and it is faced down. So this is also a function.
[tex]y=ax^2+bx+c[/tex] wit [tex]a \neq 0[/tex] willl always be a parabola.
If [tex]a>0[/tex] then it is open up.
If [tex]a<0[/tex] then it is open down.
Upwards and downward parabolas will always be functions.
[tex]x=ay^2+by+c[/tex] are also parabolas but these open to the left or right. These will not be functions because they will not pass the vertical line test.