5-6
![](http://images0.cnblogs.com/blog/571409/201310/08170655-5c0179b040a346eea6ed7ff153aaa1e4.png)
#include<stdio.h> float result_real,result_imag; int main(void) { float imag1,imag2,real1,real2; void complex_prod(float real1,float imag1,float real2,float imag2); void complex_add(float real1,float imag1,float real2,float imag2); printf("Enter 1st complex number(real and imaginary):"); scanf("%f%f",&real1,&imag1); printf("Enter 2nd complex number(real and imaginary):"); scanf("%f%f",&real2,&imag2); complex_add(real1,imag1,real2,imag2); printf("addition of complex is %f+%fi\n",result_real,result_imag); complex_prod(real1,imag1,real2,imag2); printf("product of complex is %f+%fi\n",result_real,result_imag); return 0; } void complex_add(float real1,float imag1,float real2,float imag2) { result_real=real1+real2; result_imag=imag1+imag2; } void complex_prod(float real1,float imag1,float real2,float imag2) { result_real=real1*real2-imag1*imag2; result_imag=real1*imag2+real2*imag1; }