What is the vertex form of #y= x^2+2x-4 #?

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Answer 1 · 2015-12-31T22:19:39

#y = (x-(-1))^2 + (-5)#

The vertex form of a quadratic equation #y = ax^2 + bx + c# is
#y = a(x-h)^2 + k# where #(h, k)# is the vertex.

To find the vertex form, we use a process called completing the square

For this particular equation:
#y = x^2 + 2x - 4#

#=> y = (x^2 + 2x + 1) - 1 - 4#

#=> y = (x+1)^2 - 5#

#:. y = (x-(-1))^2 + (-5)#

Thus we have the vertex form

#y = (x-(-1))^2 + (-5)# and the vertex is at #(-1,-5)#