Question

trignometery
help me solve them with the reasons please

Answer 1

sin (x + y) = sin(x) cos(y) + cos(x) sin(y),
cos(x + y) = cos(x) cos(y) - sin(x) sin(y),

sin(x - y) = sin(x) cos(y) - cos(x) sin(y),
cos(x - y) = cos(x) cos(y) + sin(x) sin(y),

Double Angle Identities

sin(2x) = 2 sin(x) cos(x),
cos(2x) = cos2(x) - sin2(x),
cos(2x) = 2 cos2(x) - 1,
cos(2x) = 1 - 2 sin2(x),
tan(2x) = [2 tan(x)]/[1-tan2(x)],
Half Angle Identities




Product identities




Sum to Product Identities