Again, let alpha = t, and let beta = t. Plug them into the formula that you have.2) If sin (alpha + beta) = sin (alpha) cos(beta) + cos (alpha) sin (beta), show that sin (2t) = 2 sin (t) cos (t)
replace the right side using the identity that you have from problem 2). then, divide both sides by sin(alpha) [there is something extra you have to do because you do this, check your notes] and then solve for x.3. Find all values that sin (alpha) = sin (2 alpha)
There are a few starts. It sounds like you are a ways behind in this class. You need to close the gap quickly. I personally feel that trig proofs and trig solving are some of the tougher concepts you're going to see this year because they are very unforgiving of being set aside to be done later.