Moderate -0.5 This is a 1-mark multiple choice question requiring recognition that tanh x = sinh x/cosh x, so the equation becomes sinh x = cosh²x. While it involves hyperbolic functions (a Further Maths topic), the solution requires only basic manipulation and knowledge that cosh x ≥ 1 while sinh x can equal 1 at exactly one point, making it easier than average despite being Further Maths content.
Find the number of solutions of the equation $\tanh x = \cosh x$
Circle your answer.
[1 mark]
$0 \quad 1 \quad 2 \quad 3$
\hfill \mbox{\textit{AQA Further Paper 1 2023 Q1 [1]}}