Posted by Heather on .
answer the following for the given quadratic function.
f(x)=x^2+x^28
a. what is the vertex (h,k) of f?
(h,k)=? simplify your answer and type the answer in an ordered pair
b. what is the axis of symmetry?

math 
Riana,
a. (0,8) is the vertex

math 
Riana,
b. axis of symmetry is zero.

check  math 
Reiny,
I have a feeling there is a typo.
Why would anybody have two like terms in the equation ?
should it be
f(x) = x^2 + 2x  8 ???? 
math 
Heather,
Yes, Reiny you caught the typo
It should read f(x)=x^2+2x8, thank you for catching that. So, now my answers will change that Riana gave. Right? 
math 
Reiny,
yes,
complete the square ....
f(x) = x^2 + 2x +1  1 8
= (x+1)^2  9
vertex is (1,9)
axis of symmetry: x = 1 or x+1 = 0 
math 
Riana,
then your vertex is (2,8)
and axis will be 1 
math 
Riana,
the vertex can't be (1,9) its incorrect.

math 
Reiny,
NO, check my reply

math 
Reiny,
Yes it is !
http://www.wolframalpha.com/input/?i=plot+x%5E2+%2B+2x++8