Question 748450
Look at the unit circle to see how sine of x and sine of negative x are related.  If you rotate a ray of 1 unit in the clockwise direction from the positive horizontal axis, then you have a -x.  The sine of -x is the opposite of sine of positive x.  


Your equation means,
{{{sine(x)+sine(-x)=2}}}
{{{sine(x)+(-sine(x))=2}}}
{{{sine(x)-sine(x)=2}}}
{{{highlight(0=2)}}}
FALSE.