How do you simplify the quadratic formula?

1 Answer
Dec 27, 2017

A few thoughts...

Explanation:

If you are wanting simpler versions of the quadratic formula, then here are a few thoughts...

Given a quadratic equation of the form:

ax^2+bx+c = 0ax2+bx+c=0

the roots are given by the quadratic formula:

x = (-b+-sqrt(b^2-4ac))/(2a)x=b±b24ac2a

Note that if bb is even, then the radicand b^2-4acb24ac is a multiple of 44, so we end up with a square root that can be simplified.

We can incorporate this simplification into a simplified quadratic formula for the equation:

ax^2+2dx+c = 0ax2+2dx+c=0

namely:

x = (-d+-sqrt(d^2-ac))/ax=d±d2aca

Further note that if (as is commonly the case) a=1a=1, then the roots of:

x^2+2dx+c=0x2+2dx+c=0

are:

x = -d+-sqrt(d^2-c)x=d±d2c