quadratic_equation.brz

define quadratic
# Expect: [a, b, c] to be defined

4 a c * *         # Stack: 4*a*c
b 2 **            # Stack: 4*a*c, b**2
swap -            # Stack: (b**2 - 4*a*c)

if 0 over > do    # Stack: (b**2 - 4*a*c), 0 > (b**2 - 4*a*c)
	"There's no real root." show
else
	if 0 over = do   # Stack: (b**2 - 4*a*c), 0 == (b**2 - 4*a*c)
		0.5 **       # Stack: sqrt(b**2 - 4*a*c)
		b -1 *       # Stack: sqrt(b**2 - 4*a*c), -b
		swap +       # Stack: -b + sqrt(b**2 - 4*a*c)

		a 2 *        # Stack: -b + sqrt(b**2 - 4*a*c), 2*a
		/            # Stack: (-b + sqrt(b**2 - 4*a*c)) / 2*a

		"Root: $0" show
	else
		0.5 **     # Stack: sqrt(b**2 - 4*a*c)
		b -1 *     # Stack: sqrt(b**2 - 4*a*c), -b
		over over  # Stack: sqrt(b**2 - 4*a*c), -b, sqrt(b**2 - 4*a*c), -b
		swap -     # Stack: sqrt(b**2 - 4*a*c), -b, (-b - sqrt(b**2 - 4*a*c))
		a 2 *      # Stack: sqrt(b**2 - 4*a*c), -b, (-b - sqrt(b**2 - 4*a*c)), 2*a
		/          # Stack: sqrt(b**2 - 4*a*c), -b, ((-b - sqrt(b**2 - 4*a*c)) / 2*a)
		"Root 1: $0" show

		over over  # Stack: sqrt(b**2 - 4*a*c), -b, sqrt(b**2 - 4*a*c), -b
		swap +     # Stack: sqrt(b**2 - 4*a*c), -b, (-b - sqrt(b**2 - 4*a*c))
		a 2 *      # Stack: sqrt(b**2 - 4*a*c), -b, (-b - sqrt(b**2 - 4*a*c)), 2*a
		/          # Stack: sqrt(b**2 - 4*a*c), -b, ((-b - sqrt(b**2 - 4*a*c)) / 2*a)
		"Root 2: $0" show
	end
end
end


# You need to specify the args using the `define` keyword.
# It's a way to define named arguments for a function.
define a 1 end
define b 5 end
define c 6 end

quadratic