One point in each interval. An entire interval, between two critical points, either fulfills, or doesn't fulfill, the inequality.
For example, (x-3)(x+5) > 0; the corresponding equality is (x-3)(x+5) = 0, with the two critical points x = 3 and x = -5. The intervals that must be checked are x < -5, x between -5 and 3, and x > 3.
One variable inequality- graph the point on the number line then choose a point on the point, to the left and to the right to see what gets shaded. Two variable inequality- graph the line on grid paper then choose a point on the line, to the left and to the right to see what gets shaded.
Graphing or plotting.
Pick a test point, (the origin is the most convenient unless the line of the inequality falls on it), and plug it into the same linear inequality. If the test point makes the inequality true, then shade that side of the line. If the test point makes the inequality false, then shade the opposite side of the line.
It is because all measurements are taken from that point: it is the fixed point of reference.
An equality defines a specific point (or points). An inequality can define an interval.
One variable inequality- graph the point on the number line then choose a point on the point, to the left and to the right to see what gets shaded. Two variable inequality- graph the line on grid paper then choose a point on the line, to the left and to the right to see what gets shaded.
When graphing a linear inequality, the first step is to replace the inequality symbol with an equal sign to graph the corresponding linear equation. This creates a boundary line, which can be solid (for ≤ or ≥) or dashed (for < or >) depending on whether the points on the line are included in the solution set. After graphing the line, you then determine which side of the line represents the solution set by testing a point (usually the origin if it's not on the line) to see if it satisfies the original inequality. Finally, shade the appropriate region to indicate the solutions to the inequality.
Linear programming is just graphing a bunch of linear inequalities. Remember that when you graph inequalities, you need to shade the "good" region - pick a point that is not on the line, put it in the inequality, and the it the point makes the inequality true (like 0
Take a sample point from either the top or bottom of the graph. I like to use (0,0) if it is not on the line. Substitute it into the inequality and if it is true then it represents all points on that line as true and vice versa.
An open or closed circle are used to graph an inequality in one variable. An open circle is used if the value at the end point is excluded from the feasible region while a closed circle is used if the value at that point is within the accepted region.
Choose any point and substitute its coordinate into the inequality. If the inequality remains TRUE then the region containing the inequality is the one that you want. If it is false, then you want the region on the other side of the line. You can choose any point in the plane and substitute its coordinates into the inequality. The origin is usually the simplest.
Graphing inequalities on a grid involves first translating the inequality into an equation to determine the boundary line. For example, for the inequality (y < 2x + 3), you would graph the line (y = 2x + 3) as a dashed line (indicating that points on the line are not included). Next, you select a test point (usually the origin, if it’s not on the line) to determine which side of the line to shade. The shaded region represents all the solutions to the inequality.
Graphing or plotting.
When the line goes through the origin like y>3x. Notice that there is no constant added to the end.
A closed circle on a number line or graph indicates that the endpoint is included in the solution set of the inequality. This typically represents inequalities that use "less than or equal to" (≤) or "greater than or equal to" (≥). In contrast, an open circle would indicate that the endpoint is not included. Thus, a closed circle signifies that the value at that point satisfies the inequality.
I think that you are asking about the linear inequalities with two variables, so my answer is related to them. First, you have to draw the boundary line (be careful, if your inequality does not contain the equal sign, the boundary line will be a dashed line, because the points on the line are not solutions to the inequality), which divide the coordinate system in two half-planes. Second, you have to test a point on either sides of the line (the best point is the origin, (0, 0), if it is not on the boundary line). If that point satisfies the inequality, then there are all its solutions, otherwise they are to the opposite side.
In algebra, a boundary point refers to a point that marks the edge or limit of a set or region in a coordinate system. It is often associated with inequalities, where it can be included or excluded from the solution set, depending on the type of inequality used (e.g., ≤ or <). Boundary points help define the boundaries of feasible regions in graphing and optimization problems.