Column 1 Column 2

Question

(sin theta + cos theta)sq
1 + 2sin theta cos theta

Question : how do you get column 1 to be the same as column 2?? using the trig identities

Answer 1

(sin t + cos t)^2 = 1 + 2 sin t cos t ???

sin^2T + 2 sin t cos t + cos^2 t =

but sin^2 t + cos^2 t = 1 identity
so

1 + 2 sin t cos T