Point on line satisfying distance or other condition

Questions asking to find a point on a line satisfying a condition other than simple perpendicularity from an external point, such as a given distance from the origin, a specific angle, or equal distances from two points.

9 questions · Standard +0.5

Sort by: Default | Easiest first | Hardest first
Edexcel C34 2014 June Q14
14 marks Standard +0.8
14. Relative to a fixed origin \(O\), the line \(l\) has vector equation $$\mathbf { r } = \left( \begin{array} { r } - 1 \\ - 4 \\ 6 \end{array} \right) + \lambda \left( \begin{array} { r } 2 \\ 1 \\ - 1 \end{array} \right)$$ where \(\lambda\) is a scalar parameter. Points \(A\) and \(B\) lie on the line \(l\), where \(A\) has coordinates ( \(1 , a , 5\) ) and \(B\) has coordinates ( \(b , - 1,3\) ).
  1. Find the value of the constant \(a\) and the value of the constant \(b\).
  2. Find the vector \(\overrightarrow { A B }\). The point \(C\) has coordinates ( \(4 , - 3,2\) )
  3. Show that the size of the angle \(C A B\) is \(30 ^ { \circ }\)
  4. Find the exact area of the triangle \(C A B\), giving your answer in the form \(k \sqrt { 3 }\), where \(k\) is a constant to be determined. The point \(D\) lies on the line \(l\) so that the area of the triangle \(C A D\) is twice the area of the triangle \(C A B\).
  5. Find the coordinates of the two possible positions of \(D\).
Edexcel C34 2019 June Q12
13 marks Standard +0.3
  1. Relative to a fixed origin \(O\),
    the point \(A\) has position vector \(( 2 \mathbf { i } - 3 \mathbf { j } - 2 \mathbf { k } )\) the point \(B\) has position vector \(( 3 \mathbf { i } + 2 \mathbf { j } + 5 \mathbf { k } )\) the point \(C\) has position vector ( \(2 \mathbf { i } + 4 \mathbf { j } - 3 \mathbf { k }\) )
The line \(l\) passes through the points \(A\) and \(B\).
  1. Find the vector \(\overrightarrow { A B }\).
  2. Find a vector equation for the line \(l\).
  3. Show that the size of the angle \(C A B\) is \(62.8 ^ { \circ }\), to one decimal place.
  4. Hence find the area of triangle \(C A B\), giving your answer to 3 significant figures. The point \(D\) lies on the line \(l\). Given that the area of triangle \(C A D\) is twice the area of triangle \(C A B\),
  5. find the two possible position vectors of point \(D\).
Edexcel C4 2014 January Q8
15 marks Standard +0.3
8. With respect to a fixed origin \(O\), the lines \(l _ { 1 }\) and \(l _ { 2 }\) are given by the equations $$l _ { 1 } : \mathbf { r } = \left( \begin{array} { r } 2 \\ - 3 \\ 4 \end{array} \right) + \lambda \left( \begin{array} { r } - 1 \\ 2 \\ 1 \end{array} \right) , \quad l _ { 2 } : \mathbf { r } = \left( \begin{array} { r } 2 \\ - 3 \\ 4 \end{array} \right) + \mu \left( \begin{array} { r } 5 \\ - 2 \\ 5 \end{array} \right)$$ where \(\lambda\) and \(\mu\) are scalar parameters.
  1. Find, to the nearest \(0.1 ^ { \circ }\), the acute angle between \(l _ { 1 }\) and \(l _ { 2 }\) The point \(A\) has position vector \(\left( \begin{array} { l } 0 \\ 1 \\ 6 \end{array} \right)\).
  2. Show that \(A\) lies on \(l _ { 1 }\) The lines \(l _ { 1 }\) and \(l _ { 2 }\) intersect at the point \(X\).
  3. Write down the coordinates of \(X\).
  4. Find the exact value of the distance \(A X\). The distinct points \(B _ { 1 }\) and \(B _ { 2 }\) both lie on the line \(l _ { 2 }\) Given that \(A X = X B _ { 1 } = X B _ { 2 }\)
  5. find the area of the triangle \(A B _ { 1 } B _ { 2 }\) giving your answer to 3 significant figures. Given that the \(x\) coordinate of \(B _ { 1 }\) is positive,
  6. find the exact coordinates of \(B _ { 1 }\) and the exact coordinates of \(B _ { 2 }\) \includegraphics[max width=\textwidth, alt={}, center]{245bbe52-3a14-4494-af17-7711caf79b22-28_96_59_2478_1834}
Edexcel C4 2013 June Q8
9 marks Standard +0.3
  1. With respect to a fixed origin \(O\), the line \(l\) has equation
$$\mathbf { r } = \left( \begin{array} { c } 13 \\ 8 \\ 1 \end{array} \right) + \lambda \left( \begin{array} { r } 2 \\ 2 \\ - 1 \end{array} \right) \text {, where } \lambda \text { is a scalar parameter. }$$ The point \(A\) lies on \(l\) and has coordinates ( \(3 , - 2,6\) ).
The point \(P\) has position vector ( \(- p \mathbf { i } + 2 p \mathbf { k }\) ) relative to \(O\), where \(p\) is a constant.
Given that vector \(\overrightarrow { P A }\) is perpendicular to \(l\),
  1. find the value of \(p\). Given also that \(B\) is a point on \(l\) such that \(\angle B P A = 45 ^ { \circ }\),
  2. find the coordinates of the two possible positions of \(B\). \(\_\_\_\_\) \(\_\_\_\_\) \(\_\_\_\_\) \(\_\_\_\_\) \(\_\_\_\_\) \(\_\_\_\_\) \(\_\_\_\_\) \(\_\_\_\_\) \(\_\_\_\_\) \(\_\_\_\_\) \(\_\_\_\_\) \(\_\_\_\_\) \(\_\_\_\_\) \(\_\_\_\_\) \(\_\_\_\_\) \(\_\_\_\_\) \(\_\_\_\_\) \(\_\_\_\_\) \(\_\_\_\_\) \(\_\_\_\_\) \(\_\_\_\_\) \(\_\_\_\_\) Question 8 continued
OCR C4 2012 January Q7
6 marks Standard +0.3
7 The equation of a straight line \(l\) is $$\mathbf { r } = \left( \begin{array} { l } 1 \\ 0 \\ 2 \end{array} \right) + t \left( \begin{array} { r } 1 \\ - 1 \\ 0 \end{array} \right) .$$ \(O\) is the origin.
  1. Find the position vector of the point \(P\) on \(l\) such that \(O P\) is perpendicular to \(l\).
  2. A point \(Q\) on \(l\) is such that the length of \(O Q\) is 3 units. Find the two possible position vectors of \(Q\). [3]
Edexcel Paper 2 2024 June Q7
5 marks Standard +0.8
7. \begin{figure}[h]
\includegraphics[alt={},max width=\textwidth]{2ce10759-9ce6-47a1-b55d-d22082f88f55-16_330_654_246_751} \captionsetup{labelformat=empty} \caption{Figure 2}
\end{figure} Figure 2 shows a sketch of the straight line \(l\).
Line \(l\) passes through the points \(A\) and \(B\).
Relative to a fixed origin \(O\)
  • the point \(A\) has position vector \(2 \mathbf { i } - 3 \mathbf { j } + 5 \mathbf { k }\)
  • the point \(B\) has position vector \(5 \mathbf { i } + 6 \mathbf { j } + 8 \mathbf { k }\)
    1. Find \(\overrightarrow { A B }\)
Given that a point \(P\) lies on \(l\) such that $$| \overrightarrow { A P } | = 2 | \overrightarrow { B P } |$$
  • find the possible position vectors of \(P\).
  • AQA C4 2012 June Q7
    12 marks Standard +0.3
    \(\mathbf { 7 } \quad\) The line \(l _ { 1 }\) has equation \(\mathbf { r } = \left[ \begin{array} { r } 0 \\ - 2 \\ q \end{array} \right] + \lambda \left[ \begin{array} { r } 2 \\ 0 \\ - 1 \end{array} \right]\), where \(q\) is an integer. The line \(l _ { 2 }\) has equation \(\mathbf { r } = \left[ \begin{array} { l } 8 \\ 3 \\ 5 \end{array} \right] + \mu \left[ \begin{array} { l } 2 \\ 5 \\ 4 \end{array} \right]\). The lines \(l _ { 1 }\) and \(l _ { 2 }\) intersect at the point \(P\).
    1. Show that \(q = 4\) and find the coordinates of \(P\).
    2. Show that \(l _ { 1 }\) and \(l _ { 2 }\) are perpendicular.
    3. The point \(A\) lies on the line \(l _ { 1 }\) where \(\lambda = 1\).
      1. Find \(A P ^ { 2 }\).
      2. The point \(B\) lies on the line \(l _ { 2 }\) so that the right-angled triangle \(A P B\) is isosceles. Find the coordinates of the two possible positions of \(B\).
    AQA C4 2008 June Q7
    12 marks Standard +0.8
    7 The coordinates of the points \(A\) and \(B\) are ( \(3 , - 2,1\) ) and ( \(5,3,0\) ) respectively. The line \(l\) has equation \(\mathbf { r } = \left[ \begin{array} { l } 5 \\ 3 \\ 0 \end{array} \right] + \lambda \left[ \begin{array} { r } 1 \\ 0 \\ - 3 \end{array} \right]\).
    1. Find the distance between \(A\) and \(B\).
    2. Find the acute angle between the lines \(A B\) and \(l\). Give your answer to the nearest degree.
    3. The points \(B\) and \(C\) lie on \(l\) such that the distance \(A C\) is equal to the distance \(A B\). Find the coordinates of \(C\).
    SPS SPS FM Pure 2022 June Q8
    5 marks Standard +0.8
    With respect to a fixed origin \(O\), the line \(l\) has equation $$\mathbf{r} = \begin{pmatrix} 13 \\ 8 \\ 1 \end{pmatrix} + \lambda \begin{pmatrix} 2 \\ 2 \\ -1 \end{pmatrix}, \text{ where } \lambda \text{ is a scalar parameter.}$$ The point \(A\) lies on \(l\) and has coordinates \((3, -2, 6)\). The point \(P\) has position vector \((-\mathbf{i} + 2\mathbf{k})\) relative to \(O\). Given that vector \(\overrightarrow{PA}\) is perpendicular to \(l\), and that point \(B\) is a point on \(l\) such that \(\angle BPA = 45°\), find the coordinates of the two possible positions of \(B\). [5]