WolframAlfa/Mathematica how to find function local maximum on interval

Question

I have a polynomial function and i want to find it's minimum and maximum on a the interval [0, 5] with Wolfram Alphaa but i forgot the proper input.

I recall it went something like so: $x^4 + x^3 + x^2 + x + n = 0$ maximum on interval $[0, 5]$, however now it just gives the output of my input and no result.

Answer 1

This is working for me (minimize works as well):

"maximize x^4+x^3+x^2+x^1+n on [0,5]"

Here is the output.