controlling output of a trigonometric sum



On 11/17/2013 11:40 AM, Giulio Venezian wrote:
> Here is a fragment: (the %o lines are messed up)
>
> (%i59)  (t*cos(x)+t^3*cos(3*x))^2*4*cos(x);
>   
ratsimp(poissimp(%));  is pretty close.

t^6*cos(7*x)+(t^6+2*t^4)*cos(5*x)+(4*t^4+t^2)*cos(3*x)+(2*t^6+2*t^4+3*t^2)*cos(x)
but read about constraints of poissimp.

if you set powerdisp:true   you get

  (3*t^2+2*t^4+2*t^6)*cos(x)+(t^2+4*t^4)*cos(3*x)+(2*t^4+t^6)*cos(5*x)+t^6*cos(7*x)