Assignment:
Use an addition of subtraction formula to simplify the equation. Then find all solutions in the interval [0, 2*pie).
a) cos(x)*cos(λ)(x) + sin(x)*sin(2x) = 1/2
b) sin(3x)*cos(x) - cos(3x)*sin(x) = 0.
Provide complete and step by step solution for the question and show calculations and use formulas.