SOLUTION: {{{sin(a + b) = sin(a)cos(b) + cos(a)sin(b)}}} {{{cos(a + b) = cos(a)cos(b) - sin(a)sin(b)}}} {{{tan(a + b) = (tan(a) + tan(b))/(1 - tan(a)tan(b))}}} Are those correct?

Algebra ->  Trigonometry-basics -> SOLUTION: {{{sin(a + b) = sin(a)cos(b) + cos(a)sin(b)}}} {{{cos(a + b) = cos(a)cos(b) - sin(a)sin(b)}}} {{{tan(a + b) = (tan(a) + tan(b))/(1 - tan(a)tan(b))}}} Are those correct?      Log On


   

Question 49324: sin%28a+%2B+b%29+=+sin%28a%29cos%28b%29+%2B+cos%28a%29sin%28b%29
cos%28a+%2B+b%29+=+cos%28a%29cos%28b%29+-+sin%28a%29sin%28b%29
tan%28a+%2B+b%29+=+%28tan%28a%29+%2B+tan%28b%29%29%2F%281+-+tan%28a%29tan%28b%29%29
Are those correct?
Found 2 solutions by Nate, Osran_Shri:
Answer by Nate(3500) About Me  (Show Source):
You can put this solution on YOUR website!
You are correct.

Answer by Osran_Shri(18) About Me  (Show Source):
You can put this solution on YOUR website!
"Yes" all of your formulae listed are correct.
Here are some more for your reference again:
sin(A+B)=sin(A)cos(B)+cos(A)sin(B),
sin(A-B)=sin(A)cos(B)-cos(A)sin(B),
cos(A+B)=cos(A)cos(B)-sin(A)sin(B),
cos(A-B)=cos(A)cos(B)+sin(A)sin(B),
tan(A+B)=(tan(A)+tan(B))/(1-tan(A)tan(B))
tan(A-B)=(tan(A)-tan(B))/(1+tan(A)tan(B))