1
QuizMultiple Choice
Trigonometric Sum Identities
Question 1 of 10 • Precalculus
Which set of steps can be used to prove the sine sum identity, sin(x + y) = sin(x)cos(y) + cos(x)sin(y)?
Answer
A
Use the complementary relationship between sine and cosine to rewrite sin(x + y) as . Apply the cosine sum identity. Then simplify using sin(–y) = –sin(y) and cos(–y) = cos(y).
B
Use the complementary relationship between sine and cosine to rewrite sin(x + y) as . Apply the cosine sum identity. Then simplify using sin(–y) = sin(y) and cos(–y) = –cos(y).C
Use the supplementary relationship between sine and cosine to rewrite sin(x + y) as . Apply the cosine sum identity. Then simplify using sin(–y) = –sin(y) and cos(–y) = cos(y).D
Use the supplementary relationship between sine and cosine to rewrite sin(x + y) as . Apply the cosine sum identity. Then simplify using sin(–y) = sin(y) and cos(–y) = –cos(y).