Question

Prove that 2 cos(x) cos(y) = cos(x + y) + cos(x − y) Please show work, I'm really confused with trig indentities

Answer 1

Step-by-step explanation:

hope this will help you

Answer 2

Step-by-step explanation:

Sublimation is the transition of a substance directly from the solid to the gas state, without passing through the liquid state.