[[問題文>練習問題#p5d7bfb2]] #include <stdio.h> #include <math.h> int main(void) { double a, b, c, D; double x1, x2; a = 0.0000000045; b = 10; c = 1; void f(double a, double b, double c) { double D, x1, x2; D = b*b - 4*a*c; if(D >= 0) { x1 = (fabs(b) + sqrt(D)) / (2. * a); x1 = b < 0 ? x1 : -x1; if(D > 0) { x2 = c / (a * x1); printf("%lf, %lf\n", x1, x2); } else { printf("%lf\n", x1); } } } int main(void) { f(0.0000000045, 10, 1); return 0; }