Draw tangent line in step response ?

Hi all. I'm designing the PID controller. When I have drawn my step response function. I need to draw a tangent line at the maximum slope point of step response to find T1, T2 for designing PID controller(like the picture). Could you help me to do this ? This is my code and step response result.

if true
  clc
num = [0.25 0.10875];
den = [1 2.496 1.7992 0.325383 0.021463];
plant = tf(num,den);
step(plant)
end
clc
num = [0.25 0.10875];
den = [1 2.496 1.7992 0.325383 0.021463];
plant = tf(num,den);
step(plant)

Answer 1

[rupesh singh]

why u all r doing bullshit provide correct code