Question

使用Matlab无法求解出结果。希望Matlab高手能给以解答。谢谢。自己的Matlab学得很烂

[x,y]=solve('(-662563/20000*cos(319/400)*pi*x*y)*pi*（x+y)+6572370263/500000000*y*exp(-24990001/100000000)*y^2=0','x','y')

Answer 1

一个方程，只能解出一个变量。

1 求x
S = solve('(-662563/20000*cos(319/400)*pi*x*y)*pi*(x+y)+6572370263/500000000*y*exp(-24990001/100000000)*y^2=0','x')
S.x
答案：
两个解：
x=
[ 1/662563000/cos(319/400)/pi^2*(-331281500*cos(319/400)*pi^2+2*(27436858060562500*cos(319/400)^2*pi^4+43546093585640690*cos(319/400)*pi^2*exp(-24990001/100000000))^(1/2))*y]
[ 1/662563000/cos(319/400)/pi^2*(-331281500*cos(319/400)*pi^2-2*(27436858060562500*cos(319/400)^2*pi^4+43546093585640690*cos(319/400)*pi^2*exp(-24990001/100000000))^(1/2))*y]

2 求y
S = solve('(-662563/20000*cos(319/400)*pi*x*y)*pi*(x+y)+6572370263/500000000*y*exp(-24990001/100000000)*y^2=0','y')
S.y
答案：
三个解：
y=
[ 0]
[ 25/6572370263/exp(-24990001/100000000)*(331281500*cos(319/400)*pi^2+2*(27436858060562500*cos(319/400)^2*pi^4+43546093585640690*cos(319/400)*pi^2*exp(-24990001/100000000))^(1/2))*x]
[ 25/6572370263/exp(-24990001/100000000)*(331281500*cos(319/400)*pi^2-2*(27436858060562500*cos(319/400)^2*pi^4+43546093585640690*cos(319/400)*pi^2*exp(-24990001/100000000))^(1/2))*x]

Answer 2

[x,y,z]=solve('(2*10^(-4)-0.1)*x+1.075*10^3*y-10^(-3)*z+1.5*x*y-2*x*z-0.5*y*y+0.5*y*z=-0.5*10^(-7)','2*10^(-4)*x-0.04*y-2*x*y-3*y*z=-2*10^(-6)','0.04*z+2*x*z+3*y*z=4*10^(-6)','x','y','z')
0.5y*y+0.5y*z这个写错了
9月

Answer 3

给你个例子：
syms x y;
S = solve('x + y = 1','x - 11*y = 5')

S =
x: [1x1 sym]
y: [1x1 sym]
为了看到结果，取得结构体S中的元素：

S = [S.x S.y]

S =
[ 4/3, -1/3]