Question

find critical points of function f(x)=(x+4)/(x^2+5x+4)

Answer 1

Where are you stuck on?

Answer 2

what???

Answer 3

Where do you find it difficult to understand?

Answer 4

Is it the concept of the critical point or what?

Answer 5

In general, differentiation is a good idea here.
The function looks rather complex, however.
If you try to factor the denominator, maybe the formula can be simplified before differentiation. If not, you've run out of luck...