Question

y=-4x^2-8x-13 find the vertex of this parabola

Answer 1

hello : 
Y=-4x²-8x-13
   = -4(x²+2x) -13
   = -4 ((x² +2x+1)-1) -13
   = -4 (x+1)² +4 -13
Y=   -4 (x+1)² -9
the vertex is : (-1 , -9)