Question

A system of equations is given by cos x + cos y = 1.2 sin x + sin y = 1.4. (a) For each equation express y in terms of x. (2) (b) Hence solve the system for 0  x < , 0 < y < .

Answer 1

Answer:

We have to prove that. cos(x+y)= cosx*cosy-sinx*siny. From the figure, The angle of the upper triangle i.e. opposite side of the length C is x-y. Now by cosine law, ...