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

Numerical solution of equations — practice question

The curve is defined by $y = \dfrac{e^{2x}}{4x + 1}$, and $P$ is a point on it with $y$-coordinate $10$.
(i)[2]

Show that the $x$-coordinate of $P$ obeys $x = \tfrac{1}{2}\ln(40x + 10)$.

(ii)[3]

Apply the iterative relation $x_{n+1} = \tfrac{1}{2}\ln(40x_n + 10)$ with $x_1 = 2.3$ to determine the $x$-coordinate of $P$ correct to $4$ significant figures. Show each iteration to $6$ significant figures.

(iii)[4]

Determine the gradient of the curve at $P$, with the answer correct to $3$ significant figures.

(c(iii))[4]

Determine the gradient of the curve at $P$, with the answer correct to $3$ significant figures.

Worked solution & mark scheme

This 13-mark question has a full step-by-step worked solution and mark scheme. One marking point: Rearrange $\frac{e^{2x}}{4x+1}=10$ into a form $x=\ldots$ that includes $\ln$.

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