Answer:
4.a) Broken line.
4.b) True.
5.a) Solid line.
5.b) True.
Step-by-step explanation:
When graphing inequalities:
- < or > : broken line.
- ≤ or ≥ : solid line.
- < or ≤ : shade under the line.
- > or ≥ : shade above the line.
Question 4
Given inequality:
[tex]y < -\dfrac{1}{2}x+2[/tex]
a) As the "<" sign has been used, the line will be a broken line.
b) Substitute (0, 0) into the inequality:
[tex]\begin{aligned}\textsf{When $x=0$ and $y=0$}: \quad 0 & < -\dfrac{1}{2}(0)+2\\0 & < 0+2\\0 & < 2\end{aligned}[/tex]
As zero is less than 2, the solution at (0, 0) is true.
Graphing the inequality
Change the inequality sign to an equals sign, then substitute two values of x into the equation and solve for y to find two points on the line:
[tex]\begin{aligned}x=-2: \quad y &=-\dfrac{1}{2}(-2)+2\\y &=1+2\\y&=3\end{aligned}[/tex]
[tex]\begin{aligned}x=4: \quad y &=-\dfrac{1}{2}(4)+2\\y &=-2+2\\y&=0\end{aligned}[/tex]
Plot the points (-2, 3) and (4, 0).
Draw a broken straight line through the points.
Shade below the line.
Question 5
Given inequality:
[tex]2x+5y \leq 10[/tex]
a) As the "≤" sign has been used, the line will be a solid line.
b) Substitute (0, 0) into the inequality:
[tex]\begin{aligned}\textsf{When $x=0$ and $y=0$}: \quad 2(0)+5(0) &\leq 10\\0+0 &\leq 10\\0 &\leq 10\end{aligned}[/tex]
As zero is less than 10, the solution at (0, 0) is true.
Graphing the inequality
Change the inequality sign to an equals sign, then substitute two values of x into the equation and solve for y to find two points on the line:
[tex]\begin{aligned}x=-5: \quad 2(-5)+5y &=10\\-10+5y &=10\\5y &=20\\y&=4\end{aligned}[/tex]
[tex]\begin{aligned}x=5: \quad 2(5)+5y &=10\\10+5y &=10\\5y &=0\\y&=0\end{aligned}[/tex]
Plot the points (-5, 4) and (5, 0).
Draw a solid straight line through the points.
Shade below the line.
