matlab教程(张志涌)课后习题答案

第二章

%分段函数的写法
syms y x
z=int(x*y,x,0,1);
g = evalin(symengine,[' piecewise([y > 1/2,' char(z) '], [y <= 1/2, 1])'])
G=int(g,y)
g =
piecewise([1/2 < y, y/2], [y <= 1/2, 1])
G =
piecewise([1/2 < y, y^2/4], [y <= 1/2, y])
%习题2-1
class(vpa(sym(3/7+0.1),4))
%习题2-2
findsym(sym('sin(w*t)'),1)
findsym(sym('a*exp(-X)'),1)
findsym(sym('z*exp(j*th)'),1)
%习题2-3
syms x a positive
x_1=solve('x^3-44.5')
syms x unreal
x_2=solve('x^2-a*x+a^2')
syms a unreal
x_2=solve('x^2-a*x+a^2')
x_3=solve('x^2-a*x-a^2')
syms x real
evalin(symengine,'anames(Properties)')
evalin(symengine,'getprop(x)')