Target Mathematics

2.9: Cosecant–cotangent identity and equation

0606/21/O/N/18 — Question 7 · 8 marks

(i)
Show that 11cosx11+cosx=2cscxcotx\dfrac{1}{1 - \cos x} - \dfrac{1}{1 + \cos x} = 2\csc x \cot x.
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(ii)
Hence solve the equation 11cosx11+cosx=secx\dfrac{1}{1 - \cos x} - \dfrac{1}{1 + \cos x} = \sec x for 0x2π0 \le x \le 2\pi radians.
[4]