# IGCSE MATHEMATICS RELATED TO GRAPHS Please answer me Question # 8, Exercise 11 on Page 231 from following link http://tstuition.wikispaces.com/file/view/7+-+Graphs.pdf/78425265/7%20-%20Graphs.pdf...

IGCSE MATHEMATICS RELATED TO GRAPHS

Please answer me Question # 8, Exercise 11 on Page 231 from following link

http://tstuition.wikispaces.com/file/view/7+-+Graphs.pdf/78425265/7%20-%20Graphs.pdf

many thanks in advance. Please do not provide me just answers. Also give some explanations

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### 1 Answer

a) You need to draw a parallel to y axis at t = 10 s to check what is the car that is in advance.

The parallel intersects the curve A at a point. If you'll draw a parallel line to x axis, through this point, you'll meet y axis at a value in the interval [100;200].

The parallel intersects the curve B at a point. If you'll draw a parallel line to x axis, through this point, you'll meet y axis at a value in the interval [250;300].

The parallel intersects the curve C at a point. If you'll draw a parallel line to x axis, through this point, you'll meet y axis at a value in the interval [200;250].

You notice that at t = 10 s, the car B is in advance.

After 20 s, the curve representing the car A is in front.

b) The car B is in front at a distance between 200 and 400 meters and at more than 5 s and at less than 20 s.

c) When the curves representing the cars B and C are intersecting, then the cars have the same speed.

d) When the curves representing the cars A and C are intersecting, then the cars have the same speed.

v ~~ (400 - 300)/(20-15) ~~ 100/5 ~~ 20 m/s

e) The curve of the car C is above the curves of the cars A and B after 5 seconds, hence the car C is moving faster.

f) The car B starts after 5 s but then it goes faster and faster.