5.55 How to check if 2 expressions are the same?

Use evalb(). For example evalb(I*sinh(x)=sin(I*x)); gives true

The above does not always work. Only sure way is to do this

> m1 := exp(I*n*x); 
m2 := (cos(n*x)+I*sin(n*x)); 
simplify(m1-m2); 
simplify(m1-convert(m2,exp));