# How to extract the minimal value from NMinimize? [closed]

According to the manual, if I calculate

NMinimize[x^4 - 3 x^2 - x, x]


that returns {-3.51391, {x -> 1.30084}}, I can extract the minimal value -3.51391 using

x /. Last[NMinimize[x^4 - 3 x^2 + x, x]]


Now, if I want to calculate e.g.

NMinimize[x^4 - 3 x^2 - x + y^2, {x,y}]


then how do I extract the minimal value?

## closed as off-topic by Bob Hanlon, m_goldberg, Henrik Schumacher, bbgodfrey, J. M. is away♦Jan 6 at 2:54

This question appears to be off-topic. The users who voted to close gave this specific reason:

• "This question arises due to a simple mistake such as a trivial syntax error, incorrect capitalization, spelling mistake, or other typographical error and is unlikely to help any future visitors, or else it is easily found in the documentation." – Bob Hanlon, m_goldberg, Henrik Schumacher, bbgodfrey, J. M. is away
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## 1 Answer

If you mean you want to find what the minimum value of the expression is then this

First[NMinimize[x^4 - 3 x^2 - x, x]]

(*-3.5139*)


If you mean that you want both the x and y values that minimize the expression then this

{x,y}/.Last[NMinimize[x^4 - 3 x^2 - x + y^2, {x,y}]]

(*{1.3008, 0.}*)


And you can do even more interesting things, you can put any expression in front of that /. and then every x and y value inside that expression will be replaced by the values of x and y found by NMinimize, whether the expression is a list or anything else.