I really need help with problems. Can you please go into detail on how to do them?

Find the Review Preview Solve for x on the indicated domain. Begin by solving for the function. Recall that if no domain is indicated, the domain is all real numbers. Remember to use either a unit circle or wave graph as a visual reminder. a. 2 sin x - 1 = 0 b. 2+2 cos x =0 c. V2 - 2 sin x = 0 d. cos x + 3.8 =0, [0, 27] Is there a difference between cos- x and ? Explain. COS X Pre-Calculus with Trigonometry