Question

sin (a+B)
cos (a-b)
tg(a-b) ​

Answer 1

1)sin (a+b)

sin (a)cos(b)+cos (a)sin (b)

2)cos (a-b)

cos(a)cos (b)+sin(a)sin (b)

3)tg (a-b)

tan (a)-tan (b)

--------------------

1+tan(a)tan (b)