9709 P3 - Nov 2007 - Q6
1893
(i) By sketching a suitable pair of graphs, show that the equation \(2 - x = \ln x\) has only one root.
(ii) Verify by calculation that this root lies between 1.4 and 1.7.
(iii) Show that this root also satisfies the equation \(x = \frac{1}{3}(4 + x - 2 \ln x)\).
(iv) Use the iterative formula \(x_{n+1} = \frac{1}{3}(4 + x_n - 2 \ln x_n)\), with initial value \(x_1 = 1.5\), to determine this root correct to 2 decimal places. Give the result of each iteration to 4 decimal places.
