The points AAA, BBB, C C\,C and D D\,D have position vectors a=(13)\mathbf{a} = \begin{pmatrix} 1 \\ 3 \end{pmatrix}a=(13), b=(36)\mathbf{b} = \begin{pmatrix} 3 \\ 6 \end{pmatrix}b=(36), c=(75)\mathbf{c} = \begin{pmatrix} 7 \\ 5 \end{pmatrix}c=(75), d=(5k)\mathbf{d} = \begin{pmatrix} 5 \\ k \end{pmatrix}d=(5k)
Find the value of k k\,k for which D D\,D is the midpoint of BCBCBC.
Find the two values of k k\,k for which ∣AD⃗∣=25\left|\vec{AD}\right| = 2\sqrt{5}AD=25.
Find the value of k k\,k for which ABCD ABCD\,ABCD is a parallelogram.
197 exam-style questions on OCR A Level Maths 1.10 Vectors, covering 1.10.1 Vectors in two dimensions, 1.10.2 Vectors in three dimensions (A-level only), 1.10.3 Magnitude and direction of vectors, 1.10.4 Basic operations on vectors, 1.10.5 Position vectors, 1.10.6 Distance between points, 1.10.7 Problem solving using vectors, 1.10.8 Vectors in kinematics, and 1.10 Vectors. Each one has a worked solution and a mark scheme showing where the marks go.