Question

Sin 480 . Cos 690 +cos 780. Sin 1050

Answer 1

Answer:

-3/16

Explanation:

sin480˚×cos690˚×cos780˚×sin1050˚

=sin120˚×cos(-30˚)×cos60˚×sin(-30˚)

=sin(180˚-60)×cos(-30˚)×cos60˚×sin(-30˚)

=sin60˚×cos60˚×(-sin30˚)×cos30˚

=√3/2 × 1/2 × (-1/2) × √3/2

= -3/16

Answer 2

Explanation:

ANSWER

sin480cos690+cos780sin1050

=sin60cos30+cos60(−sin30)

=(√3/2)(√3/2)+(1/2)(-1/2)

=(3/4)-(1/4)

=(2/4)

=1/2