Apps. and Interpretation for IBDP Maths Ebook 1 | Page 116

Your Practice Set – Applications and Interpretation for IBDP Mathematics
Exercise 32
1. The straight line L
1
passes through the points A(0,100) and B(200, 0) .
(a) Find the gradient of L
1
.
(b) Find the equation of L
1
, giving the answer in general form.
Another straight line L
2
passes through the origin O and is perpendicular to L
1
. The
equation of L
2
is given by y �mx � c .
[2]
[3]
(c) Write down the values of m and c .
L
1
and L
2
intersects at the point C .
[2]
(d) Find the coordinates of C .
[3]
(e) Find the area of the triangle OAC .
[2]
(f) It is given that the ratio of the area of the triangle OBC to the area of the triangle
OAC is r :1. Find the value of r .
[3]
2. In the diagram below, the straight line L
1
passes through the points A( � 60, 0) and
B( � 20, 20) . The straight line L
2
passes through the point C( � 30, 0) and is parallel to L
1
.
The straight line L
3
passes through the point B and is perpendicular to L
1
. L
3
cuts the x
-axis at the point E . L
2
and L
3
intersect at the point D .
(a) Find the gradient of L
1
.
[2]
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