Question 279624
your quadratic formula is:


x = {{{(-b +- sqrt(b^2-4ac))/(2a)}}}


your quadratic equation has to be in the form of:


ax^2 + bx + c = 0


a is the coefficient of the x^2 term.
b is the coefficient of the x term.
c is the constant term.


you find the values of a,b,c and plug them into the formula.


an example:


x^2 - 4x + 3 = 0


a = 1
b = -4
c = 3


the quadratic formula is:


x = {{{(-b +- sqrt(b^2-4ac))/(2a)}}}


if b is equal to -4, then -b is equal to 4.
if a is equal to 1, then 2a is equal to 2.
if b is equal to -4, then b^2 is equal to 16.
if a is equal to 1 and c is equal to 3, then 4ac is equal to 4*1*3 = 12


you plug these values into your quadratic formula to get:


x = {{{(4 +- sqrt(16-12))/(2)}}}


you simplify this equation to get:


x = {{{(4 +- sqrt(4))/(2)}}}


you simplify this equation further to get:



x = {{{(4 +- 2)/(2)}}}


this becomes x = 6/2 = 3, or x = 2/2 = 1


x is either equal to 1 or x is equal to 3.


a graph of the equation y = x^2 - 4x + 3 looks like this:


{{{graph(600,600,-10,10,-10,10,x^2 - 4x + 3)}}}


you can see from the graph that y crosses he x-axis when x = 1 and when x = 3.


x = 1 and x = 3 are the roots of your equation.


using the quadratic formula is simply a matter of plugging in the right values for a,b,c in the equation and then solving it.