Question 1132709
-x^2+2x+4=0
The vertex has x value=-b/2a or -2/-2 or x=1.  When x=1, y=5
The graph is vertex high and opens downward moving 1 unit x to each side 1 unit y down and 2 units to each side and 2 down.
From the quadratic formula, first rewrite by multiplying by -1 to get x^2-2x-4=0
x=(1/2)(2+/- sqrt (4+16)) or 1+/- sqrt(5), or 3.2 and -1.2
these are the roots.
for the other, graph in a similar fashion and the roots are x=(1/2)(1+/- sqrt(13)), or -1.3, 2.3.  
{{{graph(300,300,-2,4,-10,10,-x^2+2x+4,-x^2+x+3)}}}