What do the a in the equation y= ax2 + bx + c tell you about the parabola? (75 points)

The EASIEST way to do it, is actually start with the form a(x-b)(x-c) or intercept form since you have intercepts  

x ints at (0,0) and (4,0) so y=ax(x-4)  

sub in (2,-4) it doesn't really matter whether or not its a vertex  

-4=2a(2-4)  

a=1  

so y=x(x-4)  

expand to get y=x^2-4x which is y=ax^2+bx+c form where a=1, b=-4, c=0

Step-by-step explanation:

isaiah walks 3 miles due north, turns and then 5 miles due east. how far is he from his starting point?

a^2 + b^2 = c^2

let c = distance from starting point.

(3)^2 + (5)^2 = c^2

9 + 25 = c^2

34 = c^2

sqrt{34} = sqrt{c^2}

sqrt{34} = c