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.