History

Help on query formulation
Improving an approximate formula. (English)
Math. Sch. (Leicester) 40, No. 3, 29 (2011).
From the text: In a recent issue of this journal, [M. Rose, “Miscellany", ibid. 39, No. 1, 27 (2010)] offered an interesting approximate formula: $\tan x =\frac{10+x}{100-x} (25\le x\le 65)$. But can we improve this formula without resorting to calculus? It seems reasonable to assume that a more accurate formula might take the form: $\tan x =\frac{x^2+Ax+B}{x^2+Cx+D}$.
Classification: G60 N50