So c=3
Because it's too late (-2, -5), 4a-2b+3=-5.
b=2a+4
So the function is ax 2+(4+2a) x+3.
Let the abscissa of the two intersection points and the X axis be x 1, x2.
According to Vieta theorem
x 1+x2=(4+2a)/a,x 1x2=3/a
Because |x 1-x2|= under the radical sign (x 1-x2) 2 = under the radical sign [(x 1+x2) 2-4x 1x2].
So (4+2a) 2/a 2-12/a =16.
16+ 16a+4a^2- 12a= 16a^2
A=4/3 or a=- 1
The second problem is to calculate the vertex coordinates, and then you can calculate the area.