2016 SAJC P1 Q8 [Modified]

2016 SAJC P1 Q8 [Modified]

Junior College 2
8 marks

The variables \(w\), \(x\) and \(y\) are connected by the following differential equations:

\(\frac{\mathrm{d}w}{\mathrm{d}x} = -\frac{3}{2}w - 2 \quad\quad (A)\)

\(\frac{\mathrm{d}y}{\mathrm{d}x} = w \qquad\qquad\quad\,\,\, (B)\)

  1. Solve equation (A) to find \(w\) in terms of \(x\).[3]
  2. Hence find \(y\) in terms of \(x\).[2]
  3. Different arbitrary constants found in part (ii) yields different solution curves. Some of the solution curves are straight lines. Write down the equation of one of these lines. On a single diagram, sketch your line together with a non-linear solution curve that has your line as an asymptote, indicating clearly any axes intercepts.[3]

Video Solution:

Video Solution

Video solution locked

A free account saves your progress; this video needs tuition enrolment.

Solution:

Solution locked

680+ questions here come with free worked solutions. A free account saves your questions and progress; this one needs tuition enrolment.

Create a free account to practise similar questions.

Answer:(i) \(w=Ae^{-3x/2}-\dfrac43\) (ii) \(y=-\dfrac{2A}{3}e^{-3x/2}-\dfrac43x+B\) (iii) e.g. line \(y=-\dfrac43x-1\), non-linear curve \(y=e^{-3x/2}-\dfrac43x-1\)

Need help? Join our JC Math tuition classes.

Learn more