Write the equation of a quadratic function with vertex at (-1,1)

f(x) = (x + 1)^2 + 1

f(x) = (x + 1)^2 - 1

f(x) = (x - 1)^2 + 1

f(x) = (x - 1)^2 - 1

Question

Write the equation of a quadratic function with vertex at (-1,1)

f(x) = (x + 1)^2 + 1
		
f(x) = (x + 1)^2 - 1
		
f(x) = (x - 1)^2 + 1
		
f(x) = (x - 1)^2 - 1

anonymous · Answer

If the vertex is (h, k), then the equation is:

y = a(x - h)^2 + k

Here, you can set a=1 and your h= -1 and k = 1.  So, just substitute at this point.

anonymous · Answer

huh..

anonymous · Answer

Since you are letting a=1, the equation is:

y = (x - h)^2 + k

So, now, you can ignore "a".  So now just put your values for h and k in.  What do you get so far?  Show your work.

anonymous · Answer

By substituting, that means where you see h and k in the equation, put the value of h and k in the equation instead.

anonymous · Answer

so its f(x) = (x - 1)^2 + 1 ?

anonymous · Answer

For the part within the parentheses, you have [x - (-1)] or (x - -1) which becomes (x + 1)

anonymous · Answer

so its this then 
f(x) = (x + 1)^2+ 1

anonymous · Answer

Yes!  Good work, you got it!

anonymous · Answer

Good luck in all of your studies and thx for the recognition!  @kimdre10