SOLUTION: i dont understand why sin(30+x) + sin(30-x) = sin30.cosx + cos30.sinx Please help me .

Algebra ->  Trigonometry-basics -> SOLUTION: i dont understand why sin(30+x) + sin(30-x) = sin30.cosx + cos30.sinx Please help me .      Log On


   

Question 757946: i dont understand why sin(30+x) + sin(30-x) = sin30.cosx + cos30.sinx
Please help me .
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
Sum And Difference Formulas.
A good online reference is oakroadsystems.com. Look for "Trig Without Tears".

sin%28a%2Bb%29+=+sin%28a%29cos%28b%29+%2B+cos%28a%29sin%28b%29
AND
sin%28a-b%29+=+sin%28a%29cos%28b%29+-+cos%28a%29sin%28b%29

JUST FOLLOW THE FORMULAS.

sin%2830%2Bx%29=sin%2830%29cos%28x%29%2Bcos%2830%29sin%28x%29
and
sine%2830-x%29=sin%2830%29cos%28x%29-cos%2830%29sin%28x%29

And you are trying to get help with the sum of those two:


SIMPLIFY.

sin%2830%29cos%28x%29%2B0%2Bsin%2830%29cos%28x%29
THE ANSWER_________highlight%282%2Asin%2830%29cos%28x%29%29___________THE ANSWER RESULT