Hi, by using a simple change of time variable : t = tf + (t0 - tf) s where s is the new time you can easily rewrite your ODE in an equilalent ODE in s with initial conditions.

Thank You Richard Epenoy

Sir, is this s is multiplied with (t0-tf) ??

Please reply.

Yes, thus your ODE dx(t)/dt=f(t,x(t)) can be rewitted as follows:

dx/ds=(t0-tf)f(tf+(t0-tf).s,x(s)) for s in [0,1]

For s=0, t=tf and for s=1, t=t0.

Best

Thank you sir@ Richard Epenoy

I am doing the solution of fractional order differential equation, I will try this

Thank you again

You're welcome