Question

How to solve a quadratic equation using the quadratic formula?

Answer 1

Let us suppose an equation of the form px²+qx+r=0 is given

We have to know how to find its roots by the quadratic formula

First,we have to compare it with,

ax²+bx+c=0

Then,

The values we obtain are a=p,b=q and c=r

Using Discriminant,

D=b²-4ac

=(q)²-4(p)(r)

=q²-4pr

Applying the Quadratic formula,

$\sf{x = \frac{ - b \pm \: \sqrt{d} }{2a} }$

Substituting the values appropriately,we get the roots as:

$\sf{x = \frac{ - q \pm \sqrt{q {}^{2} - 4pr } }{2p} } \\ \\ \implies \: \sf{x = \frac{ - q - \sqrt{q {}^{2} - 4pr } }{2p} \: \: or \: \: \frac{ - q + \sqrt{q {}^{2} - 4pr} }{2p} }$