1....kotangent(x)/1 is kotangent
2....yu hav 1 on both sides, so em kansel
3... left side hav kotan -kotan, so em kansel
4. rite side hav kosekant -kosekant, so em kansel
yu hav....2*kosekant=kotan +(1/kotan)=kotan+tan =(kosine/sine)+(sine/kosine)
=(kosine^2+sine^2)/(sine*kosine)=1/(sine*kosine)
2*kosekant= 2/sine
me dont see that (2/sine)=1/(sine*kosine)