Question

Solve the equation using the quadratic formula. Enter each solution in simplest form.

Answer 1

For this case we have the following quadratic equation:

$x ^ 2-4x + 23 = 0$

The solutions will be given by:

$x = \frac {-b \pm \sqrt {b ^ 2-4 (a) (c)}} {2a}$

Where:

$a = 1\\b = -4\\c = 23$

Substituting the values we have:

$x = \frac {- (- 4) \pm \sqrt {(- 4) ^ 2-4 (1) (23)}} {2 (1)}\\x = \frac {4 \pm \sqrt {16-92}} {2}\\x = \frac {4 \pm \sqrt {-76}} {2}\\x = \frac {4 \pm \sqrt {76i ^ 2}} {2}\\x = \frac {4 \pmi \sqrt {76}} {2}\\x = \frac {4 \pmi \sqrt {2 ^ 2 * 19}} {2}\\x = \frac {4 \pm2i \sqrt {19}} {2}\\x = 2 \pm i\sqrt {19}$

We have two roots:

$x_ {1} = 2-i \sqrt {19}\\x_ {2} = 2 + i \sqrt {19}$

ANswer:

$x_ {1} = 2-i\sqrt {19}\\x_ {2} = 2 + i\sqrt {19}$