I need help with these 3 questions please

5. Prove the identity using our regular proof format: (sint - cost)2 = 1 - sin(2t) 6. Use our regular proof format to prove two of our identities for these chapters. Be sure to follow the directions! a. Given cos(w - v) = cos(w) cos(v) + sin(w) sin (v), prove that cos(w + v) = cos(w) cos(v) - sin(w) sin (v). (USE ONLY COS(W - V) TO PROVE.) a. Use the sum and difference identities to prove that cos(2w) = cos?(w) - sin (w)