I tried to get the limit for this sqrt(-2*cos(alpha)*cos(alpha+d)+2-2*sin(alpha+d)*sin(alpha))/d, from right side

input

limit(sqrt(-2*cos(alpha)*cos(alpha+d)+2-2*sin(alpha+d)*sin(alpha))/d, d = 0, right);

return

sqrt(-signum(-2+2*cos(alpha)^2+2*sin(alpha)^2))*infinity;

when tried for next time

limit(combine(sqrt(-2*cos(alpha)*cos(alpha+d)+2-2*sin(alpha+d)*sin(alpha))/d), d = 0, right);

return

1

note that the expression evaluated is the same, but returns different answers, is there somebody know why or how to avoid maple to return wrong answers