Standard form of equation for a parabola: y=A(x-h)^2+k, (h,k)=(x,y) coordinates of vertex using given coordinates of vertex: y=A(x-1)^2-13 using given coordinates of y-intercept: -11=A(0-1)^2-13 A=2 Equation of parabola: y=2(x-1)^2-13 x-intercepts
set y=0 0=2(x-1)^2-13 2(x-1)^2=13 (x-1)^2=13/2 x-1=±√(13/2) x=1±√(13