Question

Stationary points of sinx + siny + sin (x+y) are​

Answer 1

Answer:

Step-by-step explanation:

Calling the expression  m  and focussing on just one period,

∂m/∂x = cosx siny sin(x+y) + sinx siny cos(x+y) = 0  

and

∂m/∂y = sinx cosy sin(x+y) + sinx siny cos(x+y)=0  

from which

cosxsinysin(x+y)=sinxcosysin(x+y)⇒sin(x+y)sin(x−y)=0 .

Then  x=y . From this  sinx=0  or \sin 3x=0 the latter giving  x=π/3  giving a maximum of  3$\sqrt{3}$/8 .