AI generatedGeometry and measuresGCSE Higher / IGCSE Extended

Expressing a point on a line using a parameter

Expressing a point on a line using a parameter.

  • A vector has both magnitude and direction. Reverse a route by changing its sign.
  • Use a consistent direction and match corresponding components.
  • A scalar multiple proves parallel directions. Collinearity also needs a shared point.

Example 1

and . P lies on the line AB with . Express in terms of a, and .

Subtract the starting position vector from the ending position vector. is the fraction of the whole directed vector .Use the route O → A → P.Collect the a- and -components.

0 < < 1 places P between A and ; > 1 places P beyond B; < 0 places P beyond A.

Example 2

and . P lies on the line AB with . Express in terms of a, and .

Subtract the starting position vector from the ending position vector. is the fraction of the whole directed vector BA.Use the route O → B → P.Collect the a- and -components.

0 < < 1 places P between A and ; > 1 places P beyond A; < 0 places P beyond B.

Your turn

Question 1

and . P lies on the line AB with . Express in terms of a, and .

Check answer
Subtract the starting position vector from the ending position vector. is the fraction of the whole directed vector .Use the route O → A → P.Collect the a- and -components.

0 < < 1 places P between A and ; > 1 places P beyond B; < 0 places P beyond A.

Question 2

and . P lies on the line AB with . Express in terms of a, and .

Check answer
Subtract the starting position vector from the ending position vector. is the fraction of the whole directed vector .Use the route O → A → P.Collect the a- and -components.

0 < < 1 places P between A and ; > 1 places P beyond B; < 0 places P beyond A.

Question 3

and . P lies on the line AB with . Express in terms of a, and .

Check answer
Subtract the starting position vector from the ending position vector. is the fraction of the whole directed vector BA.Use the route O → B → P.Collect the a- and -components.

0 < < 1 places P between A and ; > 1 places P beyond A; < 0 places P beyond B.

Question 4

and . P lies on the line AB with . Express in terms of a, and .

Check answer
Subtract the starting position vector from the ending position vector. is the fraction of the whole directed vector .Use the route O → A → P.Collect the a- and -components.

0 < < 1 places P between A and ; > 1 places P beyond B; < 0 places P beyond A.

Question 5

and . P lies on the line AB with . Express in terms of a, and .

Check answer
Subtract the starting position vector from the ending position vector. is the fraction of the whole directed vector BA.Use the route O → B → P.Collect the a- and -components.

0 < < 1 places P between A and ; > 1 places P beyond A; < 0 places P beyond B.