yes
Substitute the values of a, b, and c into the quadratic formula. Be sure to note that a negative value for b in the quadratic equation does not replace the negative sign in front of b in the formula. If a = 0, then the equation is linear, not quadratic. The numbers a, b, and c are the coefficients of the equation, and may be distinguished by calling them, respectively, the quadratic coefficient, the linear coefficient and the constant or free term. Quadratic equations can be solved by a process known in American English as factoring and in other varieties of English as factorising, by completing the square, by using the quadratic formula, or by graphing. Solutions to problems equivalent to the quadratic equation were known as early as 2000 BC. While factoring may not always be successful, the Quadratic Formula can always find the solution. The Quadratic Formula uses the  a ,  b , and  c  from  ax2 + bx + c , where  a ,  b , and  c  are just numbers; they are the numerical coefficients of the quadratic equation they've given you to solve. Note: When you're dealing with quadratic equations, it can be really helpful to identify a, b, and c. These values are used to find the axis of symmetry, the discriminant, and even the roots using the quadratic formula. It's no question that it's important to know how to identify these values in a quadratic equation. But now b = m /3 a so a 3 - m 3 /27 a 3 = n, i.e. a 6 - na 3 - m 3 /27 = 0. This is a quadratic equation in a 3, so solve for a 3 using the usual formula for a quadratic. Now a is found by taking cube roots and b can be found in a similar way (or using b = m /3 a). Then x = a-b is the solution to the cubic. Cardan noticed something strange when he applied his formula to certain cubics. The vertex 2, the vertex is (0,0). The vertex of a parabola can be shifted however, and this change is reflected in the standard equation for parabolas. Given a parabola y=ax 2 +bx+c, we can find the x-coordinate of the vertex of the parabola using the formula x=-b/2a.
http://sites.csn.edu/istewart/mathweb/Accuplacer/accu_alg/pdf/quadratic_sol.pdf https://en.wikipedia.org/wiki/Quadratic_equation https://en.wikipedia.org/wiki/Quadratic_equation http://www.purplemath.com/modules/quadform.htm http://www.virtualnerd.com/algebra-1/quadratic-equations-functions/graphing/graph-basics/coefficients-a-b-c http://www-history.mcs.st-and.ac.uk/HistTopics/Quadratic_etc_equations.html http://calculus.nipissingu.ca/tutorials/quadratics.html
can quadratic equation be used without b