Question

solve the equation x^2-2x-4=0 using quadratic equation​

Answer 1

answer:

The equation can be easily solved by factoring

x2−2x−4

which is done by applying the quadratic formula.

δ=b2−4ac

=(-2)2−4(1)(−4)

=4+16

=20

x1=−b+√δ2a

=2+√202

=2+√4⋅52

=2+2√52x1

=(1+√5)

x2

=−b−√δ2a

=2−√202

=2−√4⋅52

=2−2√52x2

=(1−√5)

x2−2x−4

=0

⇒(x−x1)(x−x2)

=0

⇒(x−(1+√5))(x−(1−√5))

=0

⇒x−(1+√5)

=0

=x

=1+√5

OR

x−(1−√5)

=0⇒x

=1−√5