Question involving quadratic functions

[Lliam]

Hi,

Sorry if this is not in the right place. I was unsure what section it should go in.

As I posted elsewhere I am currently getting my Grade 11 math from a learn at home program. It's an okay way to do it but at times the books can be very unexplanatory, leaving me extremely confused

I'm am not sure where to even start with this question :neutral:

"Suppose that f(x) and g(x) are both quadratic functions with graphs that open down. Explain How you know what type of function y = f(x) + g(x) must be. In which direction does the graph open? Where is the maximum point of this function in relation to the maximum points of the first two functions? Explain your answers."

I know this is probably something very simple but it has me stumped! The main point of the lesson that this question is in is completing the square (which I understand). So I believe the answer has something to do with that but I am unsure. :? If someone could even get me started on the right path I would really appreciate it!

Thanks!

- Lliam

 

[Yogi]

Open down is also called concave down.
Let's start with this, do you know what a quadratic function that is "open down" looks like? (Graphically and algebraically)

 

[Lliam]

I spoke to a tutor recently and learned how to do this. Thanks for the help guys!

- Lliam