Question

Cos 45° + Sin -90°
————————- = ?
Cos (-45°) - Sin 90°

Tolong sekalian pake caranya yang minus.

Answer 1

Gampang

cos 45 = 
sin (-90) = -sin 90 = -1

cos (-45) = cos 45 = 
sin 90 = 1

=  = 1