Additional Mathematics 0606 / Trigonometry / 3.683.68: Sec identity and equation0606/22/O/N/21 — Question 3 · 8 marksMark as done · Save for later · Show all solutions(a)Show that 1sec x−1+1sec x+1=2 cot x cosec x\dfrac{1}{\mathrm{sec}\,x - 1} + \dfrac{1}{\mathrm{sec}\,x + 1} = 2\,\mathrm{cot}\,x\,\mathrm{cosec}\,xsecx−11+secx+11=2cotxcosecx.[4]▸ Answer(b)Hence solve 1sec x−1+1sec x+1=sec x\dfrac{1}{\mathrm{sec}\,x - 1} + \dfrac{1}{\mathrm{sec}\,x + 1} = \mathrm{sec}\,xsecx−11+secx+11=secx for 0∘<x<360∘0^{\circ} < x < 360^{\circ}0∘<x<360∘.[4]▸ Answer▸ Official mark scheme← 3.67: Binomial expansion and coefficient equation3.69: Triangle with surds: side, sine and height →
