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Question: how to get rid of terms of order d^2 or greater

Question:how to get rid of terms of order d^2 or greater

itsme 764
May 03 2014
1

is there a built in command to get rid of terms of some order or greater in a given variable?

say i have:

myeq:=diff(mu[m](t), t, t) = (-2*d^2*phi[0]^2-2*phi[0]^2)*mu[m](t)/(2*C_J*phi[0]^2*L)+(J*L*sin(mu[m](t)/phi[0])*d^2+J*sin(mu[m](t)/phi[0])*L)*mu[p](t)^2/(2*C_J*phi[0]^2*L)+J*cos(mu[m](t)/phi[0])*d^3*mu[p](t)/(phi[0]*C_J)+(I_b*L*d*phi[0]^2-2*J*L*sin(mu[m](t)/phi[0])*phi[0]^2-d^2*Phi[xx]*phi[0]^2-phi[0]^2*Phi[xx])/(2*C_J*phi[0]^2*L);

and i want to get rid of all terms of O(d^2).

i know i can do this

lhs(myeq)=algsubs(d^2=0, rhs(myeq));

or

lhs(myeq)=convert(series(rhs(myeq), d=0, 2), polynom);

but I wonder if there is a built-in command. 

thanks
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