MATLAB: How to write f”’ + f’f” = 0 in matlab

Question

f''' is the third order differential.

Answer 1

YOu can write first,second and third derivative like below:

df = diff(f,t) ;   %f'
d2f = diff(f,t,t) ; % f''
d3f = diff(f,t,t,t) ; % f'''

Check below option also:

syms f(t)  
df = diff(f,t) ;
d2f = diff(df,t) ;
d3f = diff(d2f,t) ;
ode = d3f+df*d2f == 0
dsolve(ode)