Question 632055: How can you say that a Quadratic Equation is in a Standard Form?
Answer immediately. Thanks.
Answer by Theo(13342)   (Show Source):
You can put this solution on YOUR website! the standard form of a quadratic equation is y = ax^2 + bx + c
a is the coefficient of the x^2 term
b is the coefficient of the x term
c is the constant.
to find the roots, you set the equation equal to 0.
this is the same as saying that y = 0.
the standard form then becomes ax^2 + bx + c = 0
why do you set the equation equal to 0?
it's because you want to find the real roots of the equation and, by definition, the real roots of the equation are the value of x when y is equal to 0.
on a graph it's the point where the equation crosses or touches the x-axis.
if the equation does not cross the x-axis, then the equation has no real roots.
you can find the roots by factoring, but that doesn't always work.
you can always find the roots by using the quadratic equation.
that formula is:
x = (-b +/- sqrt(b^2-4ac))/(2a)
the a, and the b,and the c in that equation requires the quadratic equation to be in standard form before you can identify them.
example:
5x^2 + 3x - 7 = 0
a is equal to 5
b is equal to 3
c is equal to -7
|
|
|
