Find the minimum value of 2x2+2xy+y2−2x+2y+4over all real numbers x and y.
We can use the formula x=-b/(2a) and find the min/max value. After plugging in and solving we should have (0, y^2+2y+4) as our min/max value. Hope this helps. :)
This figure should help: the green plane just touches the bottom of the orange function.
