Answer:
Step-by-step explanation:
Given that a quadratic function(polynomial of degree 2) passes through two points (1,5) and (3,7)
The function would be of the form
[tex]y=ax^2+bx+c[/tex]
with if a>0 open up and if a<0 open down
Since passes through(1,5) and (3,7) these points satisfy the equation
[tex]5= a+b+c\\7 = 9a+3b+c[/tex]
Let us eliminate c easily
2 = 8a +2b or 4a+b =1
b =1-4a
Thus parametric equation we can write as
[tex]y=ax^2+bx+c[/tex]
[tex]y = ax^2+(1-4a)x+c[/tex]
where c is arbitrary
If a>0 this will be open up otherwise open down.