1. domain refers to the range of independent variables, such as function y=x, and the value of independent variable x is r, so the range of dependent variable y is r at this time, and the range of value refers to the range of dependent variable.

2.(x- 1)(x-6)(x+5)>0

What you said should be the "root-piercing method" in the solution of mathematical inequality in high school. This line should first pass through -5 from the lower part of the X axis and then go up.

Then pass 1 in turn.

six

3. It will happen soon

Draw a shadow and see, that's basically what you do, and that's basically what linear programming does.

This needs to be discussed. It's complicated.

5.x？ Is ≥0, so when x=0, this term is the smallest, and then the formula y? +4y+ 1=(y+2)？ -3

Therefore, when y=-2, the last three terms are at least -3.

The minimum value of both is -3.