/* The program reads three coefficients a, b, and c of equation a*x*x+b*x+c=0. If b*b-4ac is greater than or equal to zeor, the real roots of the equation is computed and printed; otherwise, the complex roots of the equation is computed and printed; */ #include #include #include "complex.h" int main(void) { float a, b, c; complex root1, root2; float square; printf("Solving the two roots of equation a*x*x+b*x+c=0.\n"); printf("Please enter three coefficients a, b, and c: "); scanf("%f %f %f", &a, &b, &c); square = b * b - 4 * a * c; if (square >= 0) { root1.re = (-b + sqrt(square)) / (2 * a); root1.im = 0.0; root2.re = (-b - sqrt(square)) / (2 * a); root2.im = 0.0; } else { root1.re = -b / (2 * a); root1.im = sqrt(-square) / (2 * a); root2.re = -b / (2 * a); root2.im = -sqrt(-square) / (2 * a); } if (zerop(add(add(multiply(r2c(a), multiply(root1, root1)), multiply(r2c(b), root1)), r2c(c))) && zerop(add(add(multiply(r2c(a), multiply(root2, root2)), multiply(r2c(b), root2)), r2c(c)))) { printf("\n"); printc(root1); printf(" and "); printc(root2); printf(" are the valid roots.\n\n"); } else { printf("\n"); printc(root1); printf(" and "); printc(root2); printf(" are not the valid roots.\n\n"); } system("pause"); return 0; }