syms
- 创建符号变量(或数组)和方程
diff
dsolve
- 与solve函数类似可以使用向量式输入
一阶微分方程$dÿ/dt=ty$
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4syms y(t)
ode = diff(y,t)== t * y
ode(t)= diff(y(t),t)== t * y(t)
ySol(t)= dsolve(ode)如果增加一个条件y(0) = 2
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2cond = y(0) == 2;
ySol(t) = dsolve(ode,cond)$(dy/dt+y)^2=1,y(0)=0.$
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4syms y(t)
ode = (diff(y,t)+y)^2 == 1;
cond = y(0) == 0;
ySol(t) = dsolve(ode,cond)$du/dt=3u+4v,dv/Sdt=−4u+3v.$
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12syms u(t) v(t)
%Define the equations using == and represent differentiation using the diff function.
ode1 = diff(u) == 3*u + 4*v;
ode2 = diff(v) == -4*u + 3*v;
odes = [ode1; ode2]
%odes(t) =
diff(u(t), t) == 3*u(t) + 4*v(t)
diff(v(t), t) == 3*v(t) - 4*u(t)
%Solve the system using the dsolve function which returns the solutions as elements of a structure.
S = dsolve(odes)