Transcript Slide 1

Locus
Learning Outcomes
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Identify the locus of a point in simple cases such as:
The loci of angles
The loci of points
The loci of lengths
Locus
Locus
Loci work is looking at a rule, and thinking about all the solutions for the rule.
A locus (plural: loci) is a path.
The locus of a point moves so that
it is always a set distance (x) from
a fixed point (O):
Locus
Locus
The locus of a line between two points moves so that it is always a set
distance (r) from the line between the two points (P and Q).
Locus
Locus
A treasure chest is buried on an island.
P and Q are two trees on this island.
The treasure chest is buried the same
distance from P as it is from Q.
The treasure chest is buried
20 metres from P.
(a) On the diagram, draw
accurately the locus
which represents all the
points which are 20
metres from P.
(b) Find the point where the
treasure chest is buried.
On the diagram, mark the
point clearly with a T.
Scale:
1cm represents 5m
Locus
Locus
A yacht leaves a port P and travels for 40km on a bearing of 060 to reach
a marker buoy B. At B the yacht turns and travels fir a further 50km due
east to reach a lighthouse L. At L the yacht turns again and travels back to
P in a straight line.
(a) Using a scale of 1cm to represent 10km, make an accurate scale
drawing of the locus of the yacht
(b) Using your scale drawing, find the actual distance between the
lighthouse and the port.
Additional Notes
Locus
Learning Outcomes:
At the end of the topic I will be able to
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Can
Do
Revise
Further
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Identify the locus of a point in simple cases such as:
The loci of angles
The loci of points
The loci of lengths