Page 9 - Focus KSSM SPM 2021 TG4.5 - Maths DLP

Mathematics SPM Chapter 6 Linear Inequalities in Two Variables
5. If the boundary of the shaded region is a solid (b) y  x + 3
line, then the points on the boundary line are
included in the region that satisfies the inequality y
given.
y x + 3
Type of x
Inequality straight Points on the O
symbol straight line
line

Dashed Not included
 or  line in the solution Solution
region.
(a) y Form 4

Solid line Included in the x 2
Form 4
 or 
solution region.
x
O
6. The following diagrams shows the region that
satisfies the given inequality. (b) y

y y x + 3
The regions do
y mx + c y mx + c not include the O x
points lie on the
x straight line
O y = mx + c.
y mx + c
5

y State the inequality that defines each of the following
shaded regions.
The regions
y mx + c y mx + c include the (a) y
points lie on the
x straight line 1
O y = mx + c. y = x – 1
—
3
y mx + c x
0
4
(b) y
Shade the region that satisfies the given linear
inequality.
x y = 2
(a) x  2
x
0
y
x 2 Solution
1
x (a) Line y = x – 1 is a solid line and the shaded
O 3
region lies above the line. Therefore, the
1
inequality is y  x – 1.
3

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06 Focus SPM Maths F4.indd 89 17/02/2021 5:24 PM