IB Maths AI HL AI 3.3 Vectors and matrix transformations questions

Exam-style questions in the shape of Paper 1 and Paper 2, with full markschemes. Read the markscheme, or type, photograph or draw your answer and get it marked.

Question 1

Paper 2Medium7 marks

A triangular inspection plate is fitted in a three-dimensional frame. From vertex OO the edges OAOA and OBOB are represented by the vectors

a=(2,1,2) m,b=(1,3,−1) m.\mathbf a=(2,1,2)\text{ m},\qquad \mathbf b=(1,3,-1)\text{ m}.

An engineer uses these edges to assess the size and orientation of the plate.

(a)

Determine the area of triangle OABOAB

[2]
(b)

Determine the acute angle between the lines OAOA and OBOB to the nearest 0.1∘0.1^\circ

[2]
(c)

Find the scalar component of a\mathbf a in the direction of b\mathbf b and the magnitude of the component of a\mathbf a perpendicular to b\mathbf b Give each answer to 3 significant figures.

[2]
(d)

Use your answers to part (c) to state whether OAOA is more nearly parallel or perpendicular to OBOB giving a reason.

[1]

Question 2

Paper 2Medium6 marks

For the first 10 hours of a survey, two vessels move in a horizontal plane at constant velocity. Their position vectors, relative to a fixed origin, are

rA(t)=(1.5, 2.0)+t(0.40, 0.30),rB(t)=(6.7, 5.1)+t(−0.35, −0.10),\mathbf r_A(t)=(1.5,\,2.0)+t(0.40,\,0.30),\qquad \mathbf r_B(t)=(6.7,\,5.1)+t(-0.35,\,-0.10),

where coordinates are in kilometres and tt is the time in hours after 08:00.

(a)

Write down the initial position vector of B relative to A, AB→(0)\overrightarrow{AB}(0)

[1]
(b)

Show that

AB→(t)=(5.2, 3.1)+t(−0.75, −0.40).\overrightarrow{AB}(t)=(5.2,\,3.1)+t(-0.75,\,-0.40).
[2]
(c)

Hence determine the time, tt and the distance between the vessels when they are closest during the 10-hour survey. Give both answers to 3 significant figures.

[3]

The best questions are still waiting

Unlock every question in this topic, then type, photograph or draw your answer and have it marked against the markscheme. Find out where you are dropping marks.