This is a preview. Log in through your library . Abstract This investigation describes quantitative relationships between circle segments (portions of a chord, tangent, secant and their co-functions) ...

Sec(a-b) = cos(a+b) / cos^2a - sin^2b I'm trying to prove this, by turning the left side into the right. I am stuck. Presumably you have already done the sum and difference formulas for sin and cos.

The Mathematical Gazette is the original journal of the Mathematical Association and it is now over a century old. Its readership is a mixture of school teachers, college and university lecturers, ...