Question

1)2+sin^2a+cos^2a
2)(1-sina)(1+sina)
3)sina cos^2a+sin^3a

Answer 1

1)2+sin^2a+cos^2a = 2 + 1 = 3
2)(1-sina)(1+sina) = 1 - sin²a = cos²a
3)sina cos^2a+sin^3a = sin a · (cos²a+sin²a) = sin a