55 lines
1.3 KiB
C
55 lines
1.3 KiB
C
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#include <stdio.h>
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#include <stdlib.h>
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#include <math.h>
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int SolveQuadraticEquation(float a, float b, float c, float *x1, float *x2)
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{
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float d; // For storing b^2 - 4*a*c
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if ( a == 0) // Not a quadratie
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{
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return -1;
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}
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// calculate and store b*b-4*a*c for testing ans use later (if OK)
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d = b*b - 4*a*c;
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if ( d < 0 )
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{
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return -1; // Complex
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}
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// If we have got to here, we can calculate x1 and x2
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*x1 = ( -b + sqrt (d)) / (2 * a); // Note the use of the * before x1 & x2
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*x2 = ( -b - sqrt (d)) / (2 * a); // to write to the relevant memory locations
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// As we got here OK, return 0 to indicate all is OK
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return 0;
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}
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int main (void )
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{
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float A,B,C,x1,x2;
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int retval;
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printf ("Please enter coefficients A,B and C separated by a space\n");
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scanf ("%f %f %f", &A, &B, &C);
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// Make use of the function
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retval = SolveQuadraticEquation(A, B, C, &x1, &x2);
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// Use the retval to determine if we can display the answers or an derror message
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if ( retval == -1 )
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{
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printf ("Not a quadratic\n");
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}
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else if (retval == -1)
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{
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printf ("The solution is complex - I cannot solve these\n");
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}
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else
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{
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printf("\nThe solutions are x1=%f, x2=%f", x1, x2);
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}
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return 0; // exit
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}
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