How do you find the vertex of a parabola #y=(-x-1)(x+7)#?

Question

2008 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2018-04-02T10:59:01

Vertex is at #(-4,9) #

#y=(-x-1)(x+7) or y= -(x+1)(x+7)# or

#y= -(x^2+8x+7) or y= -(x^2+8x)-7# or

# y= -(x^2+8x+16)+16-7# or

# y= -(x+4)^2+9#. Comparing with vertex form of

equation #y = a(x-h)^2+k ; (h,k)# being vertex we find

here #h=-4 , k=9 :.# Vertex is at #(-4,9) #

graph{(-x-1)(x+7) [-25.32, 25.3, -12.66, 12.66]} [Ans]