The parabola y = ax^2 + bx + c is graphed below. Find a + b + c. (The grid lines are one unit apart.)
The parabola passes through (-2,8), (0,0), and (2,8).
First, notice that c must be equal to 0 because when you plug in (0,0) in, you get c=0. That way, we only have to solve for 2 variables.
Now we can plug in the rest of the points, and we get the equations 8=4a−2b and 8=4a+2b.
We can set the equations equal to each other and then we get b=0 as well.
Plugging b=0 into the equations, we get a=2. So a+b+c is 2+0+0 which is 2
First, notice that c must be equal to 0 because when you plug in (0,0) in, you get c=0. That way, we only have to solve for 2 variables.
Now we can plug in the rest of the points, and we get the equations 8=4a−2b and 8=4a+2b.
We can set the equations equal to each other and then we get b=0 as well.
Plugging b=0 into the equations, we get a=2. So a+b+c is 2+0+0 which is 2