निम्नलिखित का मान निकालिए :
`(i) " "(sin 18^(@))/(cos 72^(@)) " " (ii) " " (tan 26^(@))/(cot 64^(@)) " " (iii) " " cos 48^(@) - sin 42^(@) " " (iv)" cosec " 31^(@) - sec 59^(@)`