Sin3 beta cos3 betasin beta cos beta 1 sin beta cos beta
Sin^3 beta + cos^3 beta/sin beta + cos beta = 1- sin beta cos beta
Solution
b)(sin3B+cos3B)/(sinB+cosB)
a3+b3=(a+b)(a2+b2-ab)
=(sinB+cosB)(sin2B+cos2B-sinBcosB)/(sinB+cosB)
=(sin2B+cos2B-sinBcosB)
sin2x +cos2x =1 is an identity
=(1-sinBcosB)
