Identify the best first step in a verification of the following identity. sin x + 2 sin² x cos²x+cos x = 1 a. sin¹a + 2 sin² a cos²x+cos x = (sin x + 2 sin² z) (cos²x+cos¹ x) b. sin¹ x + 2 sin² x cos²x+cos x = (sin²x + cos²x)² c. sin¹a + 2 sin² x cos²x+cos x = (1-cos r) +2 (1-cos²x) cos²x+cos¹ x d. sin¹a + 2 sin² x cos²x+cos x = sin² a (sin² x + 2) + cos²z (1 + cos² z)
