Question

xii)
sino - cos80 = (sin²0 - cos20 )
(1 - 2 sin’e cos20 )​

Answer 1

:!Question for question--

What is sino?

Answer 2

Answer:

$2cos \: 40 \: degree - \cos(20) \\ \sin20 \\ \cos40degree + ( - 2 \: sin30degree.sin10 \\ \\ \\ \sin20 \\cos40degree - cos60degree \: \: \: \: \: \: \: 2sin60degree \: sin20degree \\ sin20degree \\ \\ \\ \\ 2 \times \frac{ \sqrt{3} }{2 \\ \\ \sqrt{3}$