What is the vertex of # y= (x+8)^2-2#?

2 Answers
Feb 14, 2016

vertex# -> (x,y)-> (-8,-2)#

Explanation:

When a quadratic is in this from #x_("vertex") = (-1) xx b#

where #b-> (x+b)^2#

In truth, if the original equation was of form:
#y=ax^2+b+c#..............................(1)

and #k# is a corrective value and you write equation (1) as:

#y=a(x+b/a)^2+k+c#

Then #x_("vertex")=(-1)xxb/a#

However, in your case, #a=1#
'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
#x_("vertex")= (-1)xx8 =-8#

Having found this just substitute into the original equation to find the value of #y_("vertex")#

So we have: #y=( (-8)+8)^2-2" "=" "-2#

so the vertex# -> (x,y)-> (-8,-2)#

Tony B

Feb 14, 2016

( -8 , -2 )

Explanation:

The equation of a parabola in vertex form is :

# y = (x - h)^2 + k#
where (h , k ) are the coords of the vertex.

here # y = (x +8 )^2 -2 #

and by comparison h = -8 and k = -2 → vertex = (-8 , -2 )
graph{(x+8)^2-2 [-10, 10, -5, 5]}