c programming

Summary of Quadratic Equation Activity

Main Program

• if 3 numbers provided on command line ◦ convert and assign coefficient a ◦ convert and assign coefficient b ◦ convert and assign coefficient c ◦ if a is zero

▪ if b is zero • display error message (degenerate equation)

▪ otherwise • solve linear equation (call solve_linear and send b,c)

◦ otherwise ▪ solve quadratic equation (call solve_quad and send a,b,c)

• otherwise ◦ display error message (must provide 3 coefficients on command line)

solve_linear

• calculate x = - c / b Hint: you may need to use a cast to handle integer division

• print x

solve_quad

• if b2 – 4ac < 0 ◦ solve for 2 complex solutions (call solve_complex and send a,b,c)

• otherwise ◦ solve for 2 real solutions (call solve_real and send a,b,c)

solve_real

• calculate x1 Hint: x1 = (-b + sqrt(b*b-4*a*c))/(2*a);

• calculate x2 • print x1 and x2

solve_complex

• calculate real part of solution Hint: x_real = -b/2a

• calculate imaginary part of solution Hint: x_imag= sqrt(b2 – 4ac)/2a

• print the real part and imaginary parts separated by a plus sign and followed by the letter i Hint: printf(“%f + %fi\n”, x_real, x_imag);

• print the real part and imaginary parts separated by a minus sign and followed by the letter i