# Thread: function min and vertex

1. ## function min and vertex

The function f(x) = x^2 - 18x + 83 achieves its minimum at (9,2). If g(x) = f(x-4)-3, where is the vertex of g(x)?

Thanks

2. ## Re: function min and vertex

What do you know about how the operations $\displaystyle f(x)\mapsto f(x+c)$ and $\displaystyle f(x)\mapsto f(x)+x$ change the graph of f(x)? What are your difficulties in applying this knowledge to this problem?

3. ## Re: function min and vertex

I'm not sure if I'm understanding the problem correctly. I know there's a way of getting the vertex, but I'm just not sure whether or not I'm missing something else.

4. ## Re: function min and vertex

Originally Posted by jonathanraxa
I'm not sure if I'm understanding the problem correctly. I know there's a way of getting the vertex, but I'm just not sure whether or not I'm missing something else.
Well, all the problem is asking is to find the vertex of g(x). If you don't understand a particular phrase or word or if you see alternative readings of the problem, feel free to ask about them. Also, feel free to to post your solution to be checked.

5. ## Re: function min and vertex

You are told where the vertex of y= f(x) is. Whoever assigned this problem expects you to know that replacing "x" with "x- a" shifts the graph right "a" places and adding "b" to the end of the function (g(x)= f(x)+ b) moves the graph up "b" places.

6. ## Re: function min and vertex

Originally Posted by jonathanraxa
The function f(x) = x^2 - 18x + 83 achieves its minimum at (9,2). If g(x) = f(x-4)-3, where is the vertex of g(x)?

Thanks
Lol, are you in Kelly's class? Yea i need help on this question too, I only have 1 more chance. Is the answer (5,-3)?

7. ## Re: function min and vertex

Originally Posted by Chuka