yer point...(1,-9) tell me parabola hav vertikal axis & it kerv DOWN
parabola formula for vertikal axis...(x-h)^2 =4a(y-k)
weer (h,k)="vertex"...thats the top av this parabola
yu giv h=k=3
then yu gotta figger out a value for a so that kerv go thru (1,-9)
parabola kerv down, so a is negativ
me leev that part tu yu