(viii.) The quadratic equation is the equation of two expressions, monomial or multinomial, none of the terms involving any power of x except x and x 2 .
(iii.) In solving a quadratic equation by the method of ï¿½ 38 (viii.) we may be led to a result which is apparently absurd.
In his Treatise of Algebra (1685) he distinctly proposes to construct the imaginary roots of a quadratic equation by going out of the line on which the roots, if real, would have been constructed.
The value of such a fraction is the positive root of a quadratic equation whose coefficients are real and of which one root is negative.
Consider the general quadratic equation ax 2 + bx + c = 0 where a 0.