Find the value of cos 1°. cos 2°. cos 3°. ........ cos 89° - sin 1°. sin 2°. sin 3°. ........ sin 89°

cos 1 .cos 2 .cos 3.......cos 89 - sin 1 .sin 2 .sin 3.....sin 89

=cos (90-89) .cos (90-88) .cos (90-87).......cos (90-1) - sin 1 .sin 2 .sin 3......sin 89

=sin 89 .sin 88 .sin 87.......sin 3 .sin 2 .sin 1 - sin 1 .sin 2 .sin 3......sin 89  [as cos (90-A) = sin A]

=sin 1 .sin 2 .sin 3......sin 89 - sin 1 .sin 2 .sin 3......sin 89

= 0