jika sin x = a dan 90° < x < 180° maka nilai cos (90° + x) + sin (180° - x) + cos (180° + x ) = ...
Matematika
inaa205
Pertanyaan
jika sin x = a dan 90° < x < 180° maka nilai cos (90° + x) + sin (180° - x) + cos (180° + x ) = ...
1 Jawaban
-
1. Jawaban ariyat
cos (90 + x) + sin (180 - x) + cos (180 + x)
= -sin x + sin x + cos x
= -a + a + cos (90 + x)
= -sin x
= -a