Answer:
[tex]y=-\frac{7}{18}x^2+\frac{41}{18}x+\frac{64}{9}[/tex]
Step-by-step explanation:
We need to write a quadratic equation so we can use standard quadratic equation:
[tex]y=ax^2+bx+c[/tex]
Plug the given points to get three equations.
for (7,4), we plug x=7 and y=4
[tex]4=a(7)^2+b(7)+c[/tex]
[tex]4=49a+7b+c[/tex] ...(i)
similarly using other two points, we get:
[tex]1=4a-2b+c[/tex] ...(ii)
[tex]9=a+b+c[/tex] ...(iii)
Now we solve those three equations by any method like substitution, or matrices or by any method and get:
[tex]a=-\frac{7}{18},\ b=\frac{41}{18},\ c=\frac{64}{9}[/tex]
Now plug these values into [tex]y=ax^2+bx+c[/tex], we get final equation as:
[tex]y=-\frac{7}{18}x^2+\frac{41}{18}x+\frac{64}{9}[/tex]
