cos(sin–135+sin–1513+sin–13365) is equal to : [2025]
(2)
cos(sin–135+sin–1513+sin–13365)
=cos(tan–134+tan–1512+tan–13356)
=cos(tan–1(34+512)(1–34·512)+tan–13356)
=cos(tan–15633+tan–13356)
=cos[cot–1(3356)+tan–1(3356)]
=cos(π2)=0 (∵ tan–1x + cot–1x=π2)