How to solve an integral with a straight vertical line?

Question

Mathematics

Help me understand what a straight vertical line does when solving this integral and how did you get such an answer?

Answer 1

This solution is based on the Newton-Leibniz formula.
The vertical line does not carry any meaning, and is nothing more than a strikethrough. Behind the line are the upper and lower limits of integration.

Answer 2

It separates -2, 0 from everything else, obviously.

Answer 3

In fact, the definite integral is always a number. in the geometric sense, the integral expresses the area of ​​a certain figure.
that is, according to this figure, your numbers and 0 and -2 describe straight lines perpendicular to the X axis. To calculate the integral, you need to first substitute the upper limit in the expression next to which there is a vertical bar and then the lower one and subtract the second from the first result. The fact that the solution turned out to be a negative result indicates that within the given limits of integration, the graph of the function lies below the X axis. Something like this.