使用sympy dsolve进行简单的谐波运动会返回错误的解决方案

Question

所以我尝试使用sympy的dsolve函数来解决简单谐波运动的非常简单的情况，即：

我是这样做的：

w = sympy.symbols('ω', real = True, positive=True, nonzero=True)
t = sympy.symbols('t', real = True)
x = sympy.symbols('x')

eq = sympy.diff(sympy.diff(x(t), t), t) + w**2*x

sympy.pprint(sympy.dsolve(eq, x(t)))

当我这样做时，我得到以下解决方案：

而不是我期望的或。

为什么会这样？

Answer 1

您尚未定义d.e.正常。它应该是

.diff

请注意，您可以使用更具可读性的eq = x(t).diff(t,2) + w**2*x(t) 方法

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

int main(){

char gen;
char edu[3];
int exi;
float yos;

printf("This program finds out the salary of an employee\nnow if you are graduate then enter g and if you post graduate then enter pg here :-  ");

scanf("%s",edu);
printf("now enter the yers of service of an employee here :- ");
scanf("%f",&yos);
printf("now if you are female then enter f and if you are male then enter m here :- ");
scanf(" %c",&gen);
printf("salary of an employee is ");
if (gen == 'm')
{
    if((strcmp(edu, "pg") == 0) && yos>=10)
       printf("1500");
    else if((strcmp(edu, "g") == 0) && yos>=10)
        printf("1000");
    else if((strcmp(edu, "pg") == 0) && yos<10)
        printf("10000");
    else if((strcmp(edu, "g") == 0) && yos<10)
        printf("7000");
}
else
{
    if((strcmp(edu, "pg") == 0) && yos>=10)
        printf("12000");
    else if((strcmp(edu, "g") == 0) && yos>=10 )
        printf("9000");
    else if(yos <10 && (strcmp(edu, "pg") == 0))
        printf("10000");
    else if((strcmp(edu, "g") == 0) && yos <10)
        printf("6000");
    else
        printf("i dont know!!!!! ");
}
printf("\nnow enter any digit to exit\n");
scanf("%d",&exi);
printf("you enterd %d , thus good bye",exi);

return 0;
}