412 Transformation geometry (Chapter 20)
EXERCISE 20E
1 Copy these diagrams and perform the stretch with the given invariant line IL and scale factork:
ab
cd
2
ab
3 Find the image of:
a (3,¡1) under a stretch with invariantx-axis and scale factor 4
b (4,5)under a stretch with invariantx-axis and scale factor 2
c (¡ 2 ,1) under a stretch with invarianty-axis and scale factor^12
d (3,¡4) under a stretch with invarianty-axis and scale factor^32
e
4 Find the image of triangle ABC if A(1,2),B(4,1)and C(2,5)
a invariant line y=1and scale factor k=2
b invariant line x=¡ 1 and scale factor k=^12.
5aThe object rectangle OABC is mapped onto the image
rectangle OA^0 B^0 C^0.
Describe fully the single transformation which has
occurred.
IL
A B
C
k¡=¡2
IL
A
B
C
D
k¡= ¡Qw_
IL
P
Q
R
S k¡= 1¡Qw_ IL
X
Y
Z
W
k¡= ¡Qe_
y
x
O
2
IL
y¡=¡-2
P
Q
R
S
k¡=¡¡Qw_
4
y
x
O
x¡=¡1
IL
2
2
A
B
C
k¡=¡¡Ew_
y
O x
3
4 A
A'
B
B'
C
3 C'
(2,3) under a stretch with invariant line y=¡x and scale factor^12.
are its vertices as it is stretched with:
Copy and perform the stretch with given invariant line IL and scale factor :k
IGCSE01
cyan magenta yellow black
(^05255075950525507595)
100 100
(^05255075950525507595)
100 100
Y:\HAESE\IGCSE01\IG01_20\412IGCSE01_20.CDR Wednesday, 22 October 2008 1:34:35 PM PETER