Core Connections Algebra 2, 2013
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Core Connections Algebra 2, 2013 View details
2. Section 4.2
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Exercise 86 Page 193

What points are included in the first inequality that may not be included in the second inequality?

See solution.

Practice makes perfect

To draw the inequalities, we must first find their boundary lines.

Boundary Lines

To draw the boundary lines, we will treat the inequalities as equations. |c|c| [-1em] Inequality & Equation -2pt [-0.7em] y≤ 2x-2 & y= 2x-2 -2pt [0.5em] [-0.7em] y<2x-2 & y=2x-2 [0.5em]

These equations represent straight lines written in slope-intercept form. Each line has a slope of m=2 and a y-intercept of b=-2. With this information, we can graph their lines. The only difference when graphing them is that we will dash the line of the second inequality. This is because this inequality is strict.

Shading

To complete the graphs we have to shade the correct side of each line. We can do that by testing a point that is not on any of the boundary lines. The easiest point we can choose is the origin. |c|c|c| [-0.8em] (x,y) & Inequality & Evaluate [0.2em] [-1em] ( 0, 0) & 0? ≤2( 0)-2 & 0≰-2 * [0.7em] [-1em] ( 0, 0) & 0? <2( 0)-2 & 0 ≮-2 * [0.7em] Since the origin produces a false statement for both inequalities, we should shade the side of the lines that does not contain the origin. We end up with the following diagram.

As we can see, the second inequality excludes the boundary line from the solution set whereas the first inequality does not .