Long Questions (Question 2)


Long Questions (Question 2)

Question 2:
(a) Transformation P is a reflection in the line x = m.
Transformation T is a translation (  4 2 ) .
Transformation R is a clockwise rotation of 90o about the centre (0, 4).
(i) The point (6, 4) is the image of the point ( –2, 4) under the transformation P.
State the value of m
(ii) Find the coordinates of the image of point (2, 8) under the following combined transformations:
(a) T2,
(b) TR.

(b) Diagram below shows trapezium CDFE and trapezium HEFG drawn on a Cartesian plane.

(i) HEFG is the image of CDEF under the combined transformation WU.
Describe in full the transformation:
(a) U                                       (b) W
(ii) It is given that CDEF represents a region of area 60 m2.
Calculate the area, in m2, of the region represented by the shaded region.

Solution:
(a)(i)
( 6,4 )P( 2,4 ) m= 6+( 2 ) 2 =2

(a)(ii)

(a) (2, 8) → T → (6, 6) → T → (10, 4)
(b) (2, 8) → R → (4, 2) → T → (8, 0)

(b)(i)(a)
U: An anticlockwise rotation of  90o about the centre A (3, 3).

(b)(i)(b)
Scale factor= HE CD = 4 2 =2
W: An enlargement of scale factor 2 with centre B (3, 5).

(b)(ii)
Area of HEFG = (Scale factor)2 x Area of object
                             = 22 x area of CDEF
                             = 4 x 60
                             = 240 m2
Therefore,
Area of the shaded region
= Area of HEFG – area of CDEF
= 240 – 60
= 180 m2