Apps. and Interpretation for IBDP Maths Ebook 1 | Page 109

31
Paper 2 –Miscellaneous Problems
Example
The straight line L
1
passes through the points A(0, 3) and B(6, 6) .
(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 and is parallel to L
1
.
[2]
[3]
(c) Write down the equation of L
2
, giving the answer in slope-intercept form.
C is the mid-point of AB .
[2]
(d) Find the coordinates of C .
Another straight line L
3
passes through the point C and is perpendicular to L
1
.
[2]
(e) Find the equation of L
3
, giving the answer in general form.
(f) Find the x -intercept of L
3
.
L
2
and L
3
intersects at the point D .
[3]
[2]
10
(g) Find the coordinates of D .
[3]
Solution
(a) The gradient of L
1
6�
3
� (M1) for valid approach
6 � 0
1
� A1 N2
2
[2]
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