Question

BANTU NOMOR 8-9
PAKAI CARA YG JLS DAN LENGKAP​

Answer 1

8. sin240 + sin225 + cos315

= sin(180+60) + sin(180+45) + cos(360-45)

= (-sin60)+(-sin45)+cos45

= (-1/2 √3)+(-1/2 √2)+(1/2 √2)

= -1/2 √3

9. (sin270.cos315-tan135)/(sin150.cos225)

=(sin(180+90).cos(360-45)-tan(180-45))/(sin(180-30).cos(180+45))

=((-sin90).cos45-(-tan45))/(sin30.(-cos45))

=((-1).(1/2 √2)-(-1))/((1/2).(-1/2 √2))

=((-1/2 √2)+1)/(-1/4 √2)

= (-1/2 √2)/(-1/4 √2) + 1/(-1/4 √2)

= 2 + (-4/√2)

= 2 - (4/2) √2

= 2-2√2