Question

Answer 1

a, \(M=sin^220^o+cos^230^o-sin^240^o-sin^250^o+cos^260^o+sin^270^o\)

\(=sin^220^o+cos^230^o-sin^240^o-cos^240^o+sin^230^o+cos^220^o\)

\(=\left(sin^220^o+cos^220^o\right)+\left(cos^230^o+sin^230^o\right)-\left(sin^240^o+cos^240^o\right)\)

\(=1+1-1=1\)

Answer 2

b: \(\cos75^0< \sin25^0< \cos58^0< \sin41^0=\cos49^0\)