Derivative within an integration

following equation have to be solved:

SG = (W/2*g) * integral(@f,0,84) % result should be SG

f = [ diff(V^2) / (T - D - Ff) ] % function to be inegrated

% with: T and D being dependent on V, like this:

V=0:0.2:100

T =3*(2.5*1e5 - 450.*V)

D=cD*0.5*rho*(V.^2)*S

thanks a lot!