Im having a hard time finding the intervals where the function: `f[x_] := x^2 - 4x + 7 Cos[x]` is increasing and decreasing using mathematica. I tried using `FindRoot` but it's not too accurate because the curve has inflection points beyond just the zeroes.[![enter image description here][1]][1]


  [1]: https://i.sstatic.net/p0wcp.jpg

I did this so far, which is wrong. I'm trying to find where it increases and decreases on the interval $[-4,4]$