Question 1019431
To prove
{{{sin(theta+60)+sin(theta-60)=sin(theta)}}}
expand sum and difference formulas and get
{{{(sin(theta)cos(60) + sin(60)cos(theta))+(sin(theta)cos(60) - sin(60)cos(theta)) = sin(theta)}}}
You can see that the 2nd and 4th terms cancel out...we get
{{{sin(theta)cos(60) + sin(theta)cos(60) = sin(theta)}}}
Since cos 60 = 1/2, we get
{{{sin(theta) = sin(theta)}}}