Function y = |x + 1| + |x + 2| + |x + 3|, when x=______ When y has a minimum value, the minimum value is equal to______ ．

Function y = |x + 1| + |x + 2| + |x + 3|, when x=______ When y has a minimum value, the minimum value is equal to______ ．

When x ≤ - 3, y = - 3x-6; when - 3 ＜ x ≤ - 2, y = - x; when - 2 ＜ x ≤ - 1, y = x + 4; when x ＞ - 1, y = 3x + 6; when x = - 3, y = 3, when x = - 2, y = 2, when x = - 1, y = 3, so when x = - 2, the minimum value of Y is 2

The value range of the function is Y > = 1, and the analytic expression of the function can be?

1.y=x^2 +1
2. The absolute value of y = x + 1

Why is the range of the analytic expression after substitution the same as that before substitution?

The essence of the exchange method is to deal with it as a whole,
If t = √ (x + 1), t ≥ 0
In fact, the radical and integral on the right are treated as a number t
The form of "formula" is changed, while "value" remains unchanged
"Deformation value unchanged"
It's identical deformation