神马作文网熟悉mathematica的高手,请问解方程组得不出结果问题.
来源：学生作业帮 编辑：神马作文网作业帮 分类：数学作业 时间：2024/11/19 17:03:40
熟悉mathematica的高手,请问解方程组得不出结果问题.
Wp = 200 Pi;
Ws = 300 Pi;
Rp = 1;
Rs = 16;
NSolve[{x - Wp/Power[10^(Rp/10) - 1,(2*y)^-1] == 0,
x - Ws/Power[10^(Rs/10) - 1,(2*y)^-1] == 0},{x,y}]
我想要计算x和y,可是总得不出来,是不是有什么问题?
错误显示：
NSolve::nsmet:This system cannot be solved with the methods available to NSolve.>>
out:= NSolve[{-200 (-1 + 10^(1/10))^(-(1/(2 y))) \[Pi] + x ==
0,-300 (-1 + 10 10^(3/5))^(-(1/(2 y))) \[Pi] + x == 0},{x,y}]
Wp = 200 Pi;
Ws = 300 Pi;
Rp = 1;
Rs = 16;
NSolve[{x - Wp/Power[10^(Rp/10) - 1,(2*y)^-1] == 0,
x - Ws/Power[10^(Rs/10) - 1,(2*y)^-1] == 0},{x,y}]
我想要计算x和y,可是总得不出来,是不是有什么问题?
错误显示：
NSolve::nsmet:This system cannot be solved with the methods available to NSolve.>>
out:= NSolve[{-200 (-1 + 10^(1/10))^(-(1/(2 y))) \[Pi] + x ==
0,-300 (-1 + 10 10^(3/5))^(-(1/(2 y))) \[Pi] + x == 0},{x,y}]
Solve和NSolve都是解代数方程的,对超越方程要用FindRoot并给定初值,此时只能求得数值解.改写如下:
Wp = 200 Pi;
Ws = 300 Pi;
Rp = 1;
Rs = 16;
FindRoot[{x - Wp/Power[10^(Rp/10) - 1,(2*y)^-1] == 0,
x - Ws/Power[10^(Rs/10) - 1,(2*y)^-1] == 0},{{x,1},{y,1}}]
结果为
{x -> 700.9275972,y -> 6.177981243}
Wp = 200 Pi;
Ws = 300 Pi;
Rp = 1;
Rs = 16;
FindRoot[{x - Wp/Power[10^(Rp/10) - 1,(2*y)^-1] == 0,
x - Ws/Power[10^(Rs/10) - 1,(2*y)^-1] == 0},{{x,1},{y,1}}]
结果为
{x -> 700.9275972,y -> 6.177981243}