Question

I forgot how to get the range of a function like this: f(x)=x^2-4x+9. please help!

Answer 1

I know the domain is \[(-\infty,\infty)\]

Answer 2

I find the range by putting it in vertex form and identifying the vertex/if it opens upward or downward. I dont know if thats the easiest way though. Do you know how to do that?

Answer 3

using the -b/2a?

Answer 4

look at your graph, it is the y values that are valid for the function

Answer 5

its without graphing, but using the vertex form I get [-5,infinity). thanks!!

Answer 6

the graph will just verify the range for you, just a double check

Answer 7

Shouldnt the 5 be positive?