Apps. and Interpretation for IBDP Maths Ebook 1 | Page 117

(b) Find the equation of L
1
, giving the answer in general form.
(c) Find the equation of L
2
, giving the answer in slope-intercept form.
(d) Find the equation of L
3
, giving the answer in slope-intercept form.
(e) Find the coordinates of D .
(f) Hence, find the area of the triangle CDE .
[3]
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3. In the diagram below, the straight line L
1
passes through the points A(0, a ) and
4
B(30, 0) . The gradient of L
1
is � . Another straight line L
2
passes through the points
3
B and E(90, 45) , and is perpendicular to L
1
. The points C(3 cc , ) and D lie on L
2
and
AE respectively such that CD is parallel to L
1
.
10
(a) Find the value of a .
(b) Find the equation of L
1
, giving the answer in general form.
(c) Find the equation of L
2
, giving the answer in slope-intercept form.
(d) Find the value of c .
It is also given that DE � 15 13 and CD � 30 .
(e) Find the length of CE .
(f) Hence, find the area of the triangle CDE .
[2]
[3]
[3]
[2]
[3]
[2]
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