Mathematics 9709 · AS & A Level · Numerical solution of equations

Numerical solution of equations — practice question

(a)[2]

By sketching an appropriate pair of graphs, show that the equation $\ln x = 3x - x^2$ has one real root.

(b)[2]

Use calculation to verify that the root is between $2$ and $2.8$.

(c)[3]

Apply the iterative formula $x_{n+1} = \sqrt{3x_n - \ln x_n}$ to find the root correct to $2$ decimal places. Record the outcome of every iteration to $4$ decimal places.

Worked solution & mark scheme

This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: Sketch a suitable graph, for example $y=\ln x$

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI