Find the range of the function
f(x)= (x^2+14x+9)/(x^2+2x+3)
as x varies over all real numbers.
Here is a graphical solution:
https://www.desmos.com/calculator/a1zcrvy8vu
I need to explain the answer so how do I find the range looking at the graph
The range is the set of all possible y values.
So the range is -5<=y<=4?
That is what it appears to be from the graph.
Of course it could be 4.99 or 4.001 rather than 4 but [-5,4] is close and probably correct.