Please help me with a precalc assignment! Given: A. sin(x) B. cos(x) C. cos(y) D. sin(y)

Use the drop-down menus in the derivation of the cosine sum identity:

sin(x + y)

= cos (StartFraction pi Over 2 EndFraction minus (x + y))

= Cosine ((StartFraction pi over 2 EndFraction minus x) minus y)

= Cosine (StartFraction pi Over 2 EndFraction minus x)

✔ C

+ Sine (StartFraction pi Over 2 EndFraction minus x)

A B C D

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

the central idea of the above passage is following;

central idea: cultural study is very important specially archaeology. grimm's stories very well cater to the importance of cultural relevance.

explanation:

femininity is conveyed through bernice's personality. she doesn't act how the other girls act and everyone thinks she is weird. she learns how to act in a way that was considered femininely appropriate at the time. she becomes so popular but her attempts to be liked end up backfiring when she is pressured into bobbing her hair. the author wrote that bernice cut off her cousin's hair in revenge for tricking her to cut her hair. this was the authors way of trying to change the way feminine is defined and the way women are expected to act.

this is what i put and it was correct

it's a way for authors to communicate with reader in this time period. books from the past can teach us about life.