Addition/Subtraction

Question 1

What is the identity for cos(u + v)?

Answer 1

cos(u + v) = cos(u)cos(v) − sin(u)sin(v)

Question 2

What is the identity for cos(u − v)?

Answer 2

cos(u − v) = cos(u)cos(v) + sin(u)sin(v)

Question 3

What is the identity for sin(u + v)?

Answer 3

sin(u + v) = sin(u)cos(v) + cos(u)sin(v)

Question 4

What is the identity for sin(u − v)?

Answer 4

sin(u − v) = sin(u)cos(v) − cos(u)sin(v)

Question 5

What is the identity for tan(u + v)?

Answer 5

tan(u + v) = (tan(u) + tan(v)) / (1 − tan(u)tan(v))

Question 6

What is the identity for tan(u − v)?

Answer 6

tan(u − v) = (tan(u) − tan(v)) / (1 + tan(u)tan(v))