Question

Sin20Cos80-Cos20Sin80

Answer 1

this is the expansion of

sin(a - b) where a = 20 and b = 80 or sin(-60)

Answer 2

I see..... thanks

Answer 3

Still need some help

Answer 4

check the question.....i think its wrong...it should be like this
sin10cos80-cos10sin80
solving......
sin(90-80)cos 80-cos(90-80)sin 80=1/cos80*cos80-1/sin80*sin 80=1-1=0

Answer 5

Well it says what I typed on the paper so......................

Answer 6

Sin20Cos80-Cos20Sin80
Sin (a-b)=sin a cos b-sin b cos a

Answer 7

\[ \sin(-60^ \circ) = - \sin (60^\circ) = - \frac{\sqrt{3}} {2} \]