why it not a number

i try to calculate the integration but it not work as i expected. it should 50 as my calculator but not

syms T;
Fx=3*T.^2-12*T+16;
Fy=2-9*T+6*T.^2-T.^3;
dx=diff(Fx, T);
dy=diff(Fy, T);
dx=dx.^2;
dy=dy.^2;
l=dx+dy;
l=sqrt(l);
i=int(l,T,0,5);

>> i

i =

int(3*((6*T - 12)^2/9 + (3*T^2 - 12*T + 9)^2/9)^(1/2), T)

Answer 1

[Voss]

syms T;
Fx=3*T.^2-12*T+16;
Fy=2-9*T+6*T.^2-T.^3;
dx=diff(Fx, T);
dy=diff(Fy, T);
dx=dx.^2;
dy=dy.^2;
l=dx+dy;
l=sqrt(l);
i=int(l,T,0,5);

i

i = 

double(i)

ans = 50