C语言程序设计教程（第三版）课后习题8.2 （C++代码）

解题思路:





注意事项:





参考代码:

#include <iostream>

#include <cmath>

//#include <iomanip>

using namespace std;

int main()

{

float a,b,c;

cin>>a>>b>>c;

float temp,temp1,temp2,temp3,x1,x2;

temp = b*b-4*a*c;

temp1 = -b/(2*a);

temp2 = sqrt(temp)/(2*a);

temp3 = sqrt(-temp)/(2*a);

if(temp > 0)

{

x1 = temp1 + temp2;

x2 = temp1 - temp2;

cout.precision(3);

cout<<"x1="<<x1;

cout<<' ';

cout.precision(3);

cout<<"x2="<<x2;

}

else if(temp == 0)

{

x1 = x2 = temp1;

cout.precision(3);

cout<<"x1="<<x1;

cout<<' ';

cout.precision(3);

cout<<"x2="<<x2;

}

else

{

cout.precision(3);

cout<<"x1="<<temp1;

cout.precision(3);

cout<<'+'<<temp3<<'i';

cout<< ' ';

cout.precision(3);

cout<<"x2="<<temp1;

cout.precision(3);

cout<<'-'<<temp3<<'i';

}

return 0;

}