How can I calculate the value in an equation?
显示 更早的评论
gamma=1.4
V_M_2 = 20;
V_M_2 = sqrt((gamma+1)/(gamma-1)) * atan(sqrt((gamma-1)/(gamma+1)*(M_2^2-1)))-atan(sqrt(M_2^2-1))
How can I find the M_2 from this equation? Thank you.
采纳的回答
Sam Chak
2022-4-26
2 个投票
Please verify if the nonlinear equation is correct.
Looks like there are no real solutions for this one.
4 个评论
Ali Deniz
2022-4-26
Torsten
2022-4-26
x values will be X^2.
Won't make a difference - no roots.
Ali Deniz
2022-4-27
@Ali Deniz, Thanks for the correction.
By the way, the nonlinear function 
has a limit, 
.
has a limit, .So, if 
, then it has roots. Please check again.
, then it has roots. Please check again.gamma = 1.4;
V_M_2 = 2.0;
% function to be solved
f = @(x) sqrt((gamma + 1)/(gamma - 1))*atan(sqrt((gamma - 1)/(gamma + 1)*(x^2 - 1))) - atan(sqrt(x^2 - 1)) - V_M_2;
% initial guess
x0 = 20;
% root-finding solver
xsol = fzero(f, x0)
xsol =
17.9584
更多回答（1 个）
Torsten
2022-4-26
I don't see a root:
gamma=1.4
V_M_2 = 20;
fun = @(M_2)V_M_2 - (sqrt((gamma+1)/(gamma-1)) * atan(sqrt((gamma-1)/(gamma+1)*(M_2-1)))-atan(sqrt(M_2-1)));
M_2 = -20:0.1:200;
plot(M_2,fun(M_2))
类别
在 帮助中心 和 File Exchange 中查找有关 Calculus 的更多信息
Translated by 
